The difficulty in pumilio is primarily with breeding and some morphs are way easier than others. For example Cristobals, Man Creek, Cauchero, El Dorado are much easier to breed. Some morphs have not been successfully bred in captivity yet. If do not care about breeding then care is fairly simple.
Here are some basics if you are considering pumilio and want to breed.
1) Use lots of leaf litter. More is better.
2) Springs are a must. If you can afford a 100 dollar frog you can buy a couple of 4 dollar cultures. Add fresh springs as often as you can. They are easy to culture, especially the tropical whites.
3) Fit as many water holding broms that you can into the vivarium.
4) The ratio should be no more than 1.1 or 1.2 for your average sized viv. (15-40 gallons). Males fight and so do females, just not quite as much as the males.
5) Proper supplementation. Rotate several different brands of supplements if you can. I have found Repashy ICB works quite well for Oophaga because of the retinol based vitamin A. I rotate ICB Rep-Cal and Herptivite to keep it well rounded.
6) Air circulation makes a big difference if you can do it. Its not a requirement by any means.
7) Don't worry about UVB light. Your glass top blocks the UV light so the benefit is quite small if any. There has always been a bit of debate over this.
8) Check into clay based substrates.
http://www.dendroboard.com/forum/parts-construction/63732-clay-substrate-how.html
http://www.dendroboard.com/forum/general-discussion/22990-ultimate-clay-based-substrate-thread.html
If I left anything out then others feel free to add to this. Enjoy your first pums. Pumilio are my personal favorite group of frogs and make up the majority of my collection. They are not overall that hard, but eventually you will want to try to breed them.