We just got back from a week aboard the Constellation. I travelled with my brother (age 39), son (age 15), sister (age 35) and her twin four year old girls, and my aunt (age 59). We all had a fabulous time.
The food, service, and facilities were excellent. Last year, we sailed on RCI's Voyager and had a wonderful time, but a very different experience.
The itinerary for this trip included some beautiful islands and the Constellation is a more elegant ship. However, the entertainment on RCI was much better (ice skating show, a circ de soleil type show, etc.). We went to the specialty restaurant which was fabulous - I was hesitant because I enjoyed the main dining room, but the food was definitely something to write home about! The Fun Factory kids program was terrific. We just can't say enough good things.