I sometimes wonder whether some people's expectations are just too high.
My daughter and I have just got off the Costa Diadema and can honestly say we had a great week. Yes, you have to pay for water at dinner, yes, the service charge is mandatory and yes, there are Italians on board - but we all knew this (or should have known this) before booking.
The ship is shiny and new, the cabins are spacious and clean, the staff are excellent, the food was fantastic (and we are definitely foodies!) and the entertainment was great. The shows were entertaining and there was music everywhere in the evening - 5 venues I think. We loved the Country Rock Club - classic rock played by real musicians!
Good size, clean, very comfortable