I've sporadically been going to Tom's for the last two years. When I first started up my freshwater tank and I had a ton of fish dying, I assumed that it was New Tank Syndrome and that my tank just needed some time. When I started getting my first fish from PetSmart however, I noticed that my fish were living longer.
I went to Tom's last week and bought a beautiful, healthy-looking oranda goldfish that I fell in love with. 48 hours later, she was belly up. :( I was going to give them the benefit of the doubt, and went back to buy another. While their selection of goldfish was lovely as always, almost half of the tanks in the store had dead fish in them. I told one of the workers there and she said, Huh. We just collected the dead fish an hour ago... I was disgusted and it made me want to cry. I even asked if they had just gotten in their fish shipments today because I know the transit can kill off otherwise healthy fish, but she said no, it'd been a few days.
Also, unrelatedly, we bought a rabbit from a breeder two years ago who warned us against buying rabbits from Tom's. She knew of other breeders who sold their inbred buns to them and had heard horror stories about pet rabbits dying under a year old.
I've given them so many chances to make things right... but I don't think I'll ever shop there again.