We chose MSC due to the price and the itinerary, which had a lot of ports we wanted to visit. Having read some of the other reviews I was pleasantly surprised to not experience most of the things everyone seems to moan about.
The service from the stewards, restaurant and bar staff was great, they were very friendly and helpful. The guy serving us in Purple Crab was particularly nice. The only time service was a bit slow was on the pool deck when it was busy but I would expect that anyway.
Embarkation (Barcelona) was quick and efficient as was debarkation. We only did one excursion which was also well organised.