Pros
Middle/floor management where I worked were fantastic people, and made the worst days bearable. General management is pretty relaxed - you get your stuff done in the time frame you're given, everything's A-OK - can't get it done in time, one of the middle management will typically do what they can do to help out. Everybody had a good sense of humor. If you've got a good work ethic and are honest, you'll move up pretty quickly - even if you're joining just as a grunt for early high school work or something similar. If you've got a skillset that you can provide, they'll often let you poke around with that skillset, even if they typically bring someone else in to do these things. Computers, inventory management - if you can do it well, they'll let you do it.
Cons
I don't believe there was a single day during the summer where it felt like we had enough people on the floor to deal with customers. Working the main customer service desk pretty much meant 8 hours of lines and falling behind on things. When I and some of the middle management brought this up to upper management, we were told that 'we were doing just fine and were overreacting, or just managing our time poorly'. That didn't fly well with some of us who were managing more than one person's job because we were understaffed and overrun. You can expect that you'll get calls on your day off to come in because not enough people were scheduled. Even if you want to take your off time to come in during the rush, you'll still be understaffed.