Hi dissers, in September I'll be going on my first disney cruise! (woohoo!). I've been on 3 carnival cruises around the Caribbean. I am going again on a 4 day on the magic. What is there to expect? Have any of you been on a carnival cruise to have something to compare this one to? I'm going with my grandparents (61&64) who are not in the best of shape, will they be okay? Thanks!