Constellation is recently refurbished, so no problems there. Like most cruise ships it is impeccably maintained. The size of the Connie was just right for my wife and I and the cabin was fine. If you are looking for a skating rink or central park or have young kids the Connie probably doesn't offer enough.
My critiques mostly lie with Celebrity. First the good: I don't confuse a lot to mean good food, the food onboard was better than Princess and we were very pleased there. The service each and every night was SLOW, not because your servers weren't trying, they just had too many tables. The entertainment including the ships troop was above average.Martini bar was a blast. Indoor therapy pool was something we loved.
The BAD: Celebrity's fees are out of line. $37/person for the speciality restaurants was ridiculous. Every day they had someone outside the buffet hawking the speciality restaurants, you would think a "no thank you" would suffice. Nope. They would follow you in offering "special deals for tonight". THIS IS AN ANNOYING PRACTICE AND CELEBRITY MUST STOP IT!