I've never lived close to a Petco- but in my experience both Superpetz and Petsmart have been very variable store by store.Well that is good that they are changing their ways, however I have not found a reason to go to either of them for over a year. In other words they still fail.
Of the two Petsmarts near me the one on the other side of town beats any LFS I've ever lived close to in terms of healthy looking fish, variety, cleanliness.