We cruised on Explorer of the Seas and had a blast. Enjoyed the Promenade and the Ice Capades Show but to be honest, we were so busy that we never got a chance to ice skate, roller/inline skate, play minature golf or experience the rock climbing wall. Our DS did inline skating but that was it.
We've cruised on Carnival twice and had a blast. Our last ship, the Spirit, was beautiful. The only thing I really miss is the Promenade...I like the open feeling.
Our next cruise is most likely going to be on Carnival or maybe RCI...don't know because we enjoy them both.