I was on the Oasis in July 2010. I loved it. No waits on or off. (Except for customs in countries, RC can’t control that.) My MIL wanted to take this cruise, I didn’t see what the big deal was about. I was wrong. We had a blast!
I am booked on the Allure for Christmas week 2011.
If you go to Cozumel, try booking a resort. We went for the day to Noche Cocum--enjoyed their beach and free drinks and wonderful food. And they only take so many people for the day so it was relaxing and no crowds to fight on port day.
Have a wonderful time.