We had a great time on our B2B; much better than I anticipated after reading all the reviews.
The ship, as it's been widely reported, is absolutely beautiful. Except for one incidence in the the Cantinella Wine Bar, the service we experienced was excellent.We never experienced any attitude or MSC stare from anyone. In fact, I thought that most of the staff went above and beyond to make sure we were happy.
We were in an Aft balcony cabin (#9225) and while there was definitely vibration, we slept great (although the mattress was hard IMO) and LOVED the cabin. Our cabin steward, Franck, and his assistant were fantastic. They brought our kids cookies every night and really went above and beyond to take care of us. We tipped them $20 at the beginning of each week and a little extra at the end.
Nice size aft balcony cabin, not that much drawer space for 4 people, oversized balcony, loved it!