The Celebrity Solstice is a fine ship. It carries a lot of people but, aside from the theatre, never felt crowded.
The ship is very clean, the cabins adequate even if a bit on the small side, the crew excellent and the food usually very good. The boarding experience was good and we were quickly settled into our cabin.
But: The small complaints. Lack of an iron in the cabin. I can understand that there may be safety reasons for this but one could be provided in a room somewhere on each deck because it is not convenient to wait for the laundry service if you just need to press an item of clothing before dinner.