So we just got back from a sailing on the Costa Luminosa. Basically, we had a great time despite the ship. The ship is generally attractive and the crew helpful, but the management on the ship is awful. They are very disorganized. Depending on who you get they may or may not be knowledgeable and can be curt. Both my daughter and I speak some Italian but not fluently and we really felt the focus of attention was on Italian speakers; we would also have enjoyed meeting some but they arrange things on board so that people speaking different languages are segregated (as at dinner).
Among my biggest complaints was that they didn't seem to open up the covered pool very much. Our first sea day it didn't open till after noon. Our final sea day, it didn't open at all and when I persisted in asking customer service why, I was finally told it was "broken." I have to say we saw no evidence of that; it was filled and the water was moving (via pump, I would say, since it didn't move in the same pattern as the water outside the ship).
We also begrudgingly took a tour of St. Petersburg since the Russian government in its infinite wisdom doesn't allow cruise passengers to wander the city by themselves unless they have paid something like $400 apiece for visas. We were looking for the least restrictive tour and settled on one that included a cruise on a canal boat. When we booked it, we were told it didn't exist in English so we booked the Italian tour. Imagine our surprise when, the evening before, we discovered that there was a meeting point in the English program for the tour that didn't exist in English. Of course, the tour office was closed by the time the program was delivered so we went to customer service. The person there called the tour office director and was told we should go to the English tour meeting point a few minutes early so they could accommodate us. Instead, the person who was coordinating there was RUDE in the extreme, refused to call the customer service person who said she should call her if there was a problem, told us there was no place for us and finished off by saying we knew what we were getting into when we booked the Italian tour. From what we discovered later, they must have opened up the tour after we booked the first day and filled it, and no one bothered to think of us even though we booked early. We really felt that we were treated poorly.
We also had problems with internet, our dinner sitting (booked late, got early and had to withstand a mob to change it even though we paid more for the cabin to guarantee our choice of sitting), food was mediocre and (in the dining room) of limited selection, and I have to say I resented the fact that they constantly blared music and activities over the loudspeaker in the pool area, where I was trying to read and rest.
I have sailed on Costa before, in the 1960s, as a teenager, going transatlantic. That was a far more pleasant though less "smooth" experience. I wouldn't say I wouldn't sail Costa again -- that would depend on ports and price -- but I will say I was extremely disappointed.