We just returned from the MSC Poesia and had a great time! We were on from the 16th-23rd of December going to the Western Carib. I had read these boards wondering how people had a bad time on a cruise and I'm still wondering!
Embarkation--honestly, it took us a while to get on the ship, but no big deal.
Ship--its beautiful. Not overly big (my wife missed a big promenade that our Royal ship had), but its very well kept. Fitness room was small for us, and a lot of their equipment didn't work. Had to wait on treadmills for a long time, but I guess it got the job done.