In the past, I considered purchasing a cockatiel from PetCo. They told me the birds were handfed. I have quite a bit of knowledge and decided to test the birds and see how they did. When the birds were removed from their cages, they were not at all friendly, were hateful, and not tame at all. These birds were not handfed. Additionally, most appeared ill and weak (as exhibited by their fluffed feathers and demeanor). So, I would not recommend purchasing pets at PetCo.
However, their supplies are well stocked, a good variety, and helpful employees that help you find what you need. Recently, I purchased a turtle dock for a new turtle that I received and they were most helpful in obtaining that item.
PROS: Wide variety, helpful employees
CONS: Questionable animal resources and care