Personally, I will probably never use a rack for anything other than hatchlings just because I don't like them. I like the ap cages. They stack, they work well, and they look pretty. They take up a bit more room but they're much more suitable than tubs for things like boas and carpets that like to climb. And if you ever decide to completely switch which species you work with it'd be easier to just redecorate the ap cage.