I like the Megaminx, and always have since I first found one in a toy store in 1984. Part of this is a love of the dodecahedron shape, but I've decided to focus on just this particular dodecahedron puzzle for this post.
I have a few different types of Megaminx and wanted to do a comparison of them for those who might not have seen their innards, as well as a review of cost and quality. I would love to get my hands on a white supernova at some point, and should probably get a new "speed megaminx" which looks almost assuredly to be the new stickered Megaminx with tiles instead of the cheap stickers. I don't have a "verision 1" of the Tiled Megaminx, and I have heard the "new" tiled megaminx that I have is an improvement. Finally I would like to get a stickered Meffert's, although I suppose I can presume it is the same as the Meffert's with tiles.
On to the review:

Here are five Megaminxes I have. From back to front (left to right):
Chinese Megminx, stickered megaminx
Meffert's tiled megaminx, Tomy Megaminx (Cubesmith stickers), Hungarian supernova
Most of them are closely related to the Meffert's. In fact, it would be nice to get a bit of history from anyone who knows about the exact timing of release to the market, and any licensing between manufacturers.
I'll start with the Tomy Megaminx.

This was my first, and for over 20 years I played with this puzzle without ever lubricating or cleaning it. Movement was so tight that many of the edge stickers came off from the sheer friction of my fingers moving the faces. I super glued them back, once messing up and permanently fixing an out of alignment sticker. Last year, when I found TwistyPuzzles.com, I saw the light and took it apart, cleaning it and lubricating it. I took off all the old stickers, including sanding down the super glued ones (blech!) and gave it some nice shiny Cubesmith stickers. Now it is a fine puzzle, although with new springs it will be better.
Note that the core is identical to the Meffert's, as is the center piece and cap. The screw is different, however, being two pieces instead of the one piece screw/washer in the Meffert's now. The spring is ever so slightly softer than the Meffert's, but not by much. Do springs get softer over 20 years? Perhaps it is the same with wear. Speaking of wear...

Note the grooves on the underside of the center piece. The Meffert's and Tomy centers are not arched, this is from decades of use

But the Tomy and Megaminx are not identical:

[Tomy on the left, Meffert's on the right]
Note that the edges are the same, even down to the pin mark on the side of the edge (not shown in this picture), but the corner of the Megaminx has a "foot" on it that as far as I can tell is completely unnecessary. Why waste the plastic I wonder?
Next we move to the new stickered Megaminx. It looks almost identical to the Meffert's, although the edges of the pieces are just a slight bit less rounded, and there are some holes in the edge and corner pieces. The corner has the same "foot" as the Meffert's:

[Stickered Megaminx left, Meffert's DIY Megaminx right]
The core is a direct copy, as is the center piece. The most immediate difference is the screw and spring. At first I thought it was riveted!


[Stickered Megaminx left, Meffert's DIY Megaminx right]
The screw of the stickered Megaminx fits inside the shaft of the center piece, and the spring is conical on both ends so it compresses down very short. Very nice design! The tension of the stickered Megaminx is softer than the Meffert's, and doesn't need replacing for speed. So far I have seen no indication of screws coming out on counterclockwise turns either, and don't expect any with this design.
The slight concave faces of the center piece are once again not arched centers, but depressions from the injection molding process. The Meffert's is in general much higher quality in terms of flat faces. Almost half of the faces of the corners on my stickered Megaminx show some sign of depressions, whereas I have seen only one on my Meffert's. For the centers this doesn't hurt, but on the corners this means very visible bubbles under the cheap stickers.
The Meffert's with stickers and Tomy had uniform sizes to their stickers, the new Stickered megaminx has stickers a bit too large, and often are misaligned and hang off the edge of the pieces. I recommend restickering with CubeSmith if you get one of these.
All of these very similar puzzles have almost exactly the same dimensions, although if I had to guess I would say the Tomy was a hair smaller (perhaps that is spring tension) than the Meffert's and the stickered Megaminx a hair larger (perhaps just the less rounded edges). All of the face cuts are such that adjoining faces do not meet in a point.
Next we move to the Tiled Megaminx, often called the Chinese Megaminx because of the location of its manufacture. Silly, as almost all puzzles are made in China these days (not the Elemental:Neon or V-Cubes though!). This has a completely different mechanism than the Meffert's, and is much closer to the Hungarian Supernova (see below). In general this is a very cheap (in price and quality) puzzle, with poor movement:

[Tiled Megaminx or "Chinese Megaminx"]
The core is a sphere with very short arms. Unlike the Meffert's style, the faces on this Megaminx meet at a point like the Supernova design. Edge and center pieces have grooves in them and corners have nubs to lock into these grooves to align the face after each turn. For a novice this is a nice "click" to help alignment, but for speed cubing it is horrible. I have heard of people removing the nubs and having good results, but haven't ever finished doing so myself.
In addition to the locking mechanism, the edges of all the pieces not rounded, and can even be sharp. This means lots of lock ups. Aside from a good price, one of the best parts of this puzzle is the soft springs. Great for stealing to improve a Meffert's Megaminx

The soft springs and sharp edges lead to pops though.
The centers of this puzzle are the only arched centers I have found in the Megaminx family. The mechanism feet are deeper in the center of the puzzle as well. With better execution on the molding and tolerances, I imagine this might lead to a superior puzzle, but these little flaws override that advantage of the design.

[Arched center of the Tiled Megaminx]
The pieces of the Tiled Megaminx are hollow, with the colored tile capping the gap. Often this is not so cleanly done, but not too bad. The colors are also not quite as bright as the Meffert's, and these tiles are flush with the puzzle face (which I prefer).
Also, this puzzle is quite a bit larger than any other in the megaminx family (about a centimeter taller). I should take proper measurements and edit this post, I don't have a caliper handy.
It comes lubricated with oil, which can be a bit messy, particularly if you open it up.
Finally we have the Hungarian Supernova. A beautiful puzzle, and hard to find, this came out the same time the Meffert's did in the early or mid 1980s. See
here for a number of good pictures.

[Core of the Hungarian Supernova]
The core is quite different from other puzzles, and the centers have arms that reach into the core. They are sprung, but I don't have the heart to remove a sticker to see the screw and spring under the center piece. It has no visible cap, so I'd have to remove the sticker to find out. I have seen some supernova's sell with poor stickering, any chance someone owns one and can take a peek for us?
Note that one corner of each center is cut off. I wonder if this was to allow a final corner to be placed easier when assembling with three adjoining cut center corners are aligned. I can't see any other reason.
This puzzle moves quite well and I have never lubricated it. I'll clean it up and try one of these days. The spring tension is good, although perhaps a tiny loose for speed solving, I would worry about too many pops if it was lubricated.
What makes this puzzle truly impressive is the incredible design of the pieces. Each corner and edge piece is actually comprised of two interlocking molded pieces. They fit together lightly but precisely and form a hollow piece that holds firm by the pressures of the puzzle:


[two piece Supernova edge and corner]
The walls are thin but the pieces strong and light. The precision of the molding for his must have been very, very good and the result holds up great after two decades (compare this with
another hungarian puzzle of the same era). When I first took it apart it was some time before one of the free pieces fell into two pieces, and I was quite surprised to discover this nice feature.
Oh yeah, the stickers are awesome. Only the orange has degraded over time, which is common for puzzles of the early 80's. Something about lead in the pigment I think. But it is a bright orange

Here I am at the end and I realize I haven't actually given the Meffert's any direct attention, just by way of comparison. Oh well, I'll have to add that later. But here is a picture with a tiled and DIY (unstickered) Meffert's as well unstickered replicas:

Now some comparisons on price and quality:
The cheapest is the Tiled Megaminx (about $6 before shipping) and you get what you pay for, it is the poorest of the lot.
Next up is the "stickered" Megaminx at about $8 or $9. It is a huge improvement over the Tiled Megaminx, and with only a bit of lubricant is ready for speed solving. You won't need to replace the springs but you will want to ditch those terrible stickers.
The Meffert's is the gold standard for speed solving, if tuned. This means spring replacements and some lubricant, and getting rid of all the flash. At $30 it is a better puzzle than the stickered clone, but not that much and probably more work for a novice to get moving smoothly. The recent problems with tiles coming off and screws coming unscrewed on counterclockwise turns (see
here for details) are unfortunate and diminish a very nice puzzle. The tiles of the Meffert's are vibrant and quite tall. Some like this, I am not sure it is my taste. Finally, the Meffert's was out of stock for years and so the true cost was in $50-$100 on eBay for quite some time. It was briefly in stock again recently but now out again [Edit: And now available again...]. So for many the clone stickered Megaminx is not only a good deal for price vs. quality, but may now be the only realistic option.
The Tomy is quite similar to the Meffert's in quality. I'd rate mine better on springs and obviously no tile or unscrewing problems. But they are quite hard to find and command a high price on eBay ($75-$100?). As a collector's item it wouldn't make much sense to use for speedsolving, but you certainly could.
The Hungarian Supernova is quite rare and a fine puzzle. Great movement, superior design and very nice stickers. Prices on eBay have fluctuated quite a bit, with one selling for $67 and another selling for $200 within a few months last year. I would expect over $100 to be the norm.
I love all these puzzles (even the Chinese Megaminx, for making the Megaminx available to so many), and if anyone has more info on ones I don't profile or aspects I haven't covered, please post here!
Dave
P.S. I would have submited this as an article, but with Sandy out of communication I don't know when it might get posted

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I finally received some of the new tiled megaminxes and figured I would add to this all in the same place. I know it was reviewed in another post, but I figured I would give my impressions as well as pictures in comparison to the Mefferts.
The new tiled Megaminx comes in both black and white. These are nice puzzles, particularly for the relatively low price ($15 or so). The movement is good, and they come lubricated with an oil (from
http://www.9spuzzles at least). They are a bit loose and easy to pop. They are also not as precise as the Mefferts or stickered Megaminx (Meffert's clone). I have gaps and inconsistencies in spacing on my puzzles. But still a good step better than the previous tiled clone of the Hungarian Supernova.
The tiles are good, and quite bright. They are shiny and smooth instead of textured like Mefferts.
The size of the puzzle is larger than the Mefferts by quite a bit, almost as large as the older Supernova cut tiled megaminx. Like this older megaminx the centers are arched and the mechanism is "deeper" in the puzzle than the Mefferts. Unlike the older megaminx with Supernova style cuts (edges meet in a point) the cuts of this megaminx are even shallower than the Megaminx, meaning a wider edge piece.
A major difference from the Mefferts and stickered (Meffert's clone) is that the pieces a hollow, making for a lighter puzzle.
I haven't yet popped the center cap to look at the screw and spring structure.
Mefferts (left) and new tiled Megaminx (right)

Arched centers:

Size difference (corners swapped):

Hollow pieces (shown from a white puzzle):

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I recently received a white stickered megaminx. Here are pictures, they confirm this is just a white plastic version of the clone stickered megaminx above. This is a good puzzle for the price.

