Not going to give you a good or bad rating for this as shops vary from location to location even in chains.
Remember these places are larger companies rather than independent LFS and have certain standards and possibly more requirements to make a sale...
That being said I have been to one where people are very knowledgeable and one where people are not and have the minimum training and experience.
What I find is a good idea to do is go in and ask questions, which are revealing in the shopkeepers knowledge eg, ask about cycling, tank requirements, water perimeters. I find this is a good way to gauge their experience. or the simple, can a buy this gold fish and put it in the 60l tank?
As for the care, go in a couple of different times and see what the tanks look like, are they well maintained? do they have dead or diseased fish? you can get a good idea of what the store is like this way.