^^Agreed here too. For example, the various types of imitators like a lot of vertical space. My imitator intermedius are rarely on the ground except to forage for food. Most pumilio will spend more time on the ground, but still need vertical space because the males like high prominent locations to call from and they like to deposit their tads higher up. Many of the larger dart frog species will spend most of their time on the ground, but they still need climbing space.
In the first case you'd want something taller than it is wide or deep. In the latter case, you'd want something shaped more like a traditional aquarium, with more floor space for its volume. For pumilio, it can be somewhere in between, but a lot of pumilio do better with larger vivs than you would think is necessary. The smallest viv I use is a 20-gal high, which houses a pair of pumilio. Most of my vivs are 29-gal longs for pairs of Tincs or Auratus, or trios of pumilio.
If I had it to do all over again, I'd go with all front opening vivs, so the Exos are a good choice. However, I often hear people say that they wish they'd gotten a larger viv and rarely hear folks saying they wish the viv was smaller. So, spending a little extra on the larger sizes would be a good investment IMO.
