Man, I had no idea this question would cause such a stir of differing opinions.
While we have never sailed
DCL, we have sailed many other lines and many of the "mega" ships such as the Grand Princess. regardless of size they all have aft, forward, and main elevator banks - three banks. The main bank is always the most heavily used no matter if the restaurants and casual dining is located in the aft or forward of the ship.
I spraigned my ankle severely on our last cruise and had to be wheel chair bound for three days. Our cabin was located mid ship as have been all our other cabins previously. We also always have traveled sans kids as they weren't born yet. We hadn't realized how much we had gotten in the habit of using the stairs and using the aft elevators until I was wheel chair bound and had to wait for elevators. It thoroughly stunk and sticks in my mind now to this day, two years later. It would take us significant extra time to wait for elevators -we actually had to begin planning for this time in order to be on time for the shows.
You all have been a great help in convincing me what to do. We are going to go with the change to aft - but its not so aft that I think it will matter much for motion or vibration. We're moving to 6608. Its not directly at the aft elevators, but its not far at all from them. Prior to this, we were really directly at the mid ship elevator banks. I have noticed in past cruises that you do notice people returning from the late shows and passing your cabin. We are early shows, early seating as we will be traveling with two small children, one under 2 years old - both with early bed times.
Thanks again everyone, oh, and this is really interesting so please, keep discussing your preferences.