I'd have to agree about the conditions of chain stores not being constant. There is one petsmart I have gone to from time to time, the employees there are great, and they keep pretty darn good care of the reptiles from what I've seen. I've never seen stuck shed on the BPs, cages are always clean, and they even use digital therms/hygrometers.
A local PetCo doesn't use digital meters, but at least it provided a humid hide for the one BP they had for sale, and that's a rarity to see in those stores.
It all depends if they actually are able to hire someone who is willing and knowledgable to take care of the animals. It's too bad that the majority of big box pet stores I have been in do not take good care of any of their animals, but there are a few that stand out.
One more thing about PetSmart: the one that we go to has sold us some fish, none of which have died and we have had one for over 3 years now. That's pretty good for chain store fish imo.
Small stores aren't always better, and in fact most of the time they are the worst of all. Small pet stores, especially the ones in malls, are where you find the puppy mill dogs for sale. The one in the burnsville center mall just pisses me off. They keep the dogs in horrible conditions, the cages are never clean, there is always at least one animal that looks sick, and almost half the puppies are ridiculous poodle crosses.. GAH! At least petsmart and petco work with local adoption agencies and shelters rather than selling dogs and cats.