Well, I know it's very simplistic, but better keep it simple. Which is better: A small enclosure with lots of enrichment and a good design, or a poorly designed large enclosure with little enrichment?
I say small and with lots of enrichment. While they may be lacking space in that one, they would at least be able to stimulate their mind, which is important in captivity. Obviously neither option is perfect, but to turn this in a selfish direction I just think about how I would rather have it. For example, if I had a tiny house but lots of things to do within that house, I would be much more satisfied than having a huge house that was bare and poorly designed.
Eh, I think it would vary from species to species, though I think enrichment would be a bit more important than space. (though that's not to say space isn't important, just that the animal would probably be better off in a small space with lots of things to do than a big one without much to do)
