We've been spoiled using AFT corner staterooms with wraparound balconies. On the Legend it's also classified as a Cat 11 suite; most of which have a separate bedroom area from the sitting area as well as a HUGE wrapaound balcony which has phenominal panaoramic views.
On the Victory, which we are cruising from NYC to Canada on the 23rd, the AFT corner staterooms are not suites but Cat 9A with the wrapaound balconies. It's a smaller interior Stateroom, also a little irregular, but there isn't a separate bedroom area. However, the Balconies are HUGE and have the same panoramic views. It really depends on what you prefer on the Victory---Room size or Balcony.
As far as the "ride" on the AFT cabins, we've had no problems. Slept like a baby. The sunrises are magnificent.You command a view of 270 degrees; the entire rear, as well as one entire side either port or starboard depending on which side your stateroom is.
The two staterooms you mentioned have a standard size balcony; not wider or deeper. Again, it's a matter of preference. One other thing. The cat 9A staterooms are not considered suites (cat 11 or 12) and therefore do not have VIP boarding privileges; unless you have 10 or more cruises with Carnival under your belt.
If you arrive early or late, then that's not a problem, as far as waiting to board. Hope u enjoy your cruise, whatever stateroom you choose :)