They don't chew on it at all, only pee and poo on all of it............
.lol. Makes it a bit of a pain to clean. they're not big chewers, i feed them things to chew on to keep their teeth worn down.
They don't slide down the slide.........
..lol. In fact, is is a piece I'll probably have to replace eventually. It's only held on by one snap b/c they're so heavy. It has 3 snaps that hold it on to the upper piece and every time you stick it back together, they go up or down one time and it falls back apart and is just barely hanging on.

Yeah I was worried about the bar spacing at first too. I kept them in a 20L gallon tank for close to a year before they graduated to the penthouse.....
.....lol.
I think yours will slow down with age. When mine were still in the store with the rest of their litter they were running all around with the rest of them. But bring them home and they figured out they have it made so they don't have to do awhole lot and their needs are still met...........
..lol.