The gerbils like it, they explore upstairs and check out things. I keep the water jottle and food dish and chew toys up there to save on room in the aquarium part. The assembly was difficult only because the hooks that hold the levels and ramp are not really great and come undone, especially cleaning it or moving it, so sometimes they are slanted or unhooked which is annoying but fixable. I think I might just zip tie and trim that up.all in all, I would still buy it.