I know our opinion will differ from most people but many people haven't actually been in the aft cabins for more than 1 cruise.
We usually cruise in suites on the aft portion of the ships. Our opinion is that although they usually have much larger balconies and less 'passenger noise', they are VERY noisy pulling into/out of ports and the ride is a lot more rough in the aft area. If you like sleeping in, good luck doing it in an aft cabin on a port day. It doesn't seem to matter if the ship is brand new with gas turbine engines or older. It's still noisy and rough.
Also, on some ships, there aren't aft elevators so the walk to the mid-ship area can be very, very long especially if you just need to run back to your cabin for something you forgot. It can really be a long trek.
For our next cruise, we're getting 2 balcony cabins that are mid-ship and adjoining. We're really looking forward to a smoother, quieter and more convenient location.