Shouldn't the blue layer be numbered or something? As is I don't see how it adds anything to the puzzle. Looks like blue pieces can only be scrambled with other blue pieces but as they are all identical they don't really add anything the the puzzle from a solving point of view.
the middle layer is a handhold, keep it more stability when playing.
maybe the middle layer stick some words will be better.
example：SMAZ CLOCK, other side : 2011