Yeah been there a couple of times when i've been over that way. I agree they do have a lot of fish in a very small place but i've never seen anything wrong with their stock and never heard of anyone having problems with fish they've bought from there. They do have a lot of fish i've not seen anywhere else and even though my visits there are months apart a lot of the more large and expensive fish are still alive and kicking between visits despite being kept in tanks we'd all consider too small.
Remember, LFS tanks like that have a very high turnover of water and very good filtration so while tanks like that are technically too small, water quality for the fish isn't suffering as much as if it was customer trying to keep the fish in a similar sized tank at home.