We sailed on the Explorer of the Seas, 9/3/2006 sailing to Bermuda. The ship was absolutely beautiful - biggest we've been on.
The best entertainment was live music and we went dancing every night. We were somewhat disappointed at the condition of some activities: the arcade was not air conditioned and video games (and one air hockey tables) often did not work. The shuffleboard equipment was old or missing.
Our cabin was fine. We were in the least expensive, inside room cabin and it was bigger than our previous cabins on Carnival (Triumph) and Norwegian (Norway). The bathroom was small - but adequate. The room was clean and well cared for. The bed was older and was ready to be replaced. The room attendant went above and beyond what was expected (we tipped her extra).