I've been ordering various puzzles via ebay recently, and I'm continually surprised at how small they are.
Yes, obviously a cuboctahedron is going to have less volume than a cube, since, to save money, it's going to have the same mechanism, but I wasn't expecting a megaminx to be as small as a cube!
I guess I expected the basic size of a "cubie" to remain unchanged across shape variations. Instead, the megaminx pieces are much smaller. Ditto for an octahedron (although, like the cuboctahedron it appears to use the same sized mechanism as the standard cube). The Skewb Diamond is about the size I expected - and scales logically from the normal Skewb.
Conversely, the Pyramorphix was much larger than I expected. I was expecting it to have parts the same size as a Pyraminx. Is that how the pocket Pyramorphix is scaled?
By those standards, though, the Trajber's Octahedron pieces I'm making are huge. I cannibalize a standard cube mechanism but the outer faces are the same distance from the center as the triangles on a cuboctahedron rather than being as small as possible. Put another way, the "cube centers" have tall caps, rather than just pyramids. That makes the cuboctahedron the intersection of my TO and a cube, but the TO itself will seem massive next to my other recently acquired toys.
I also want to make a Halpern-Meier Pyramid, but I'll need a pocket Skewb as the basis for that so it doesn't become huge.
Any other surprises out there?