Just got off the spirit. I really enjoyed it. My only complaint would be that the dining room service is slow, and the rooms are TINY. The kids program is just amazing. I wouldn't worry about the ship. It is in great shape, very clean, well staffed. You'll have a great time.
My only advice is to bring more money and less clothes, but that goes for any vacation.
By the way if you are a poker player, they had a texas hold'em tables going every night!