We have stayed on the aft before of the Sky (sister ship) and noticed only slight vibration. Nothing to bother either of us at all - and that was our first cruise. From everything I have read, we have made a great choice upgrading from our balcony cabin to an aft mini-suite.
I was in a Penthouse Aft on the Sun in January (Deck 10). I never noticed any vibration at all. In Grand Cayman, some soot from the funnel landed on the verandah. Very little though and not troublesome at all. I guess the wind was "just right" that day. This was my first aft cabin after three port balcony cabins. I will never do anything other than aft again! I am already booked on HAL Zuiderdam and Carnival Glory in aft cabins. I'm taking a bow cabin on the Jewel in January just to see (and the verandahs are larger than aft). I think you will like it.
Michael - Will do! Seriously though, I have only read terrific things about the aft minisuites.
Enjoy the Zuiderdam! We were on her this past Thanksgiving (inside cabin though). However, one of the people we met online had an aft, and they loved it! We ended up having drinks with them before dinner each night and they were very pleased with their cabin. We loved the itinerary of the Zuiderdam - it gave us plenty of time to return to our wedding beach on St John due to extra long port time in St Thomas. Have fun!
Just back last night from our NCL Sun cruise. We had aft minisuite 9278 and our friends had the mini nextdoor - 9078. The only "noise" we heard was the soothing sound of the wake down below when we would keep the door open (would stay open on it's own - a sliding glass door). No vibrations except if the ship was docking or making a hard turn in front of Sawyer Glacier to turn around - and even then, it's not like a "big" vibration. Location and views were excellent. Layout was very good - at first it seemed like a lot of furniture in a small space, but we grew to overlook that. Very spacious. More storage than we could ever need on a 7-day cruise, even with bulky Alaska clothing. The pictures I shared in the previous link are right-on-target. Definitely a terrific minisuite location!!!