I took a cruise on the MSC Opera last year, which is the Lirica's sister ship and is almost identical.
I was generally pleasantly surprised. The ships are very tastefully and expensively finished, with almost no gaudiness, and the cabin was great. There was a nice atmosphere on board despite or because of the multi nationalities, the food was good if not spectacular, apart from the pasta which was marvellous, and the entertainment better than I had hoped.
There were unfortunately no family that I could see on the Opera, but that was a different time of year and different place, so you may have company on the trip.
We will be sailing on MSC for the first time in April on the Lirica. I have been reading as much as I can about the line and have heard both good and bad just like any other cruise line. We will be traveling by ourselves so hopefully we could meet some other couples onboard to get together for drinks or dinner. We will be on the 4/18 sailing.