I'm not a fan of them. I like to sit and watch animals, along with taking photos, and it's usually impossible for me to even begin looking for the animals in the enclosures. I get that it's done to see the animals be more active, but what's the point if you can't see them to begin with?? It's extra frustrating when it's an animal I really want to see and I can't even tell if I've seen it or not, yet alone watched it (ex. every rat species other than domestic/brown/norway, basically).
The only one I've enjoyed has been Omaha. Different lights are used with different species, and there's enough that they can usually be made out. I would like to see some of them in the light, though, especially the springhaas!! The immersion helps, I think, and with it being so big, your eyes have a lot of time to adjust.