We have been on deck 7 for our two previous cruises. We really like the location. It's very easy to walk up the stairs to the pool deck (where the quick food is). You can bop down a few flights to the theater deck, etc. We almost always take the stairs on the cruise, and with deck 7, the longest trip is 5 flights, from the nightclubs on 3, usually broken up with a stop on deck 5 to pick up the kids at the childrens programs.
Our next cruise is booked on deck 2, but we're waitlisted for 7. I think 2 will be okay, but we'll probably run back to the room less often from the pool. The deck 2 location will be more convenient to the formal restaurants. Our room is under the atrium, so it's not listed as a noisy room. Several deck 2 rooms have the potential for noise from the clubs and the docking equipment. Dave from Marietta has them listed on his sites.
Other than that, I'd say choose the deck that most meets your needs. If you are the kind of person that bops back and forth between your rooms, the pool, the snack bar, etc. deck 7 would probably be best. If you are more interested in the theaters, the nightclubs, and sit down restaurants, deck 2 would be fine.
Good luck!