Just put Marble back together and I'm floored. Really impressive design. I kind of wrote off some of the praise I'd read about how elegant it is but once all the pieces came together I couldn't help but smile. It's such a pure and simple mechanical solution. I kept looking for some sort of trick but it's actually pretty straight forward.
I got it apart in just a few minutes but didn't pay close attention. No idea how long it took to reassemble. Between work and BotW I only put in a few minutes here and there over the last week and never sat down to seriously solve it until tonight.
Not sure what I'll get next but between the two I've done so far (Galaxy & Marble) I'm very pleased with Hanayama's puzzles.
Yeah, the moment I put Marble back together and understood its design was when I fell in love with these things. If you thought the difficulty of Marble was enough for now, Rattle would be my suggestion. If you want a higher difficulty, then Padlock.