I agree with the previous post, if one petsmart or petco has done me wrong they all have. And in my experience, i agree that these stores do not hire the most intelligent or concerned employees, and the reason is simply bottom dollar, they pay less than say a smaller shop may pay their smaller staff.
I am a firm believer that big box stores of any kind are what ruined personal service and knowledgeable sales people, i sell car audio, tint, and alarm for a living, at a place where our proces may be slightly higher, but the quality of installation is far superior, we outsell the best buy down the street in the car audio department, yet i still lose sales to those people who are looking for a cheap install.
when it comes to pets, the difference between 99 cent tetras and the ones i paid 2 dollars for is enormous, mine are still alive and a friend who set up a tank after mines had disease within days of coming home.
I think that the condition of the tanks is a silly way to judge the quality of the location, i have seen the petco here use ammonia based chemicals to clean tanks, sure they are clean, but not stable or safe.
in this same light my favorite LFS has tanks that have been set up for over 10 years, of course they look a little haggrd and the hard water we have in texas has taken its toll, but the tanks are stable, the fish are generally active and healthy, and the floors are wet, never trust a fish store with dry floors, means someone isnt working hard enough.
I just want to make the point that clean does not always mean safe or better. In my opinion finding a great small LFS and a salesperson you can trust to be knowledgeable is the best route to go, I have 2 guys at my LFS who have never steered me wrong, and have been really friendly in the process, its great to feel like your time is important, never gotten that from the usual highschool kid working at petco or petsmart.
It is customer SERVICE after all and you shouldnt have to track someone down to help you, they should be asking you what they can do for you, and thats my major grief with the big box stores, hourly employees tend to stand around unless told to get to work, people who work on a comission or profit share like most small privately operated lfs around here, they tend to care more about your need or situation.