This cruise was a lot of 'firsts' for me - first RCL cruise, first solo cruise, first time to the Bahamas and Keys, and first interior cabin. I chose the Majesty 4 night cruise because of the price and itinerary. The single supplement was pleasingly low (about 115%) - and the overall cruise price was very acceptable. Carnival came nowhere near with their 200% solo prices - and so lost some revenue I guess. I was a little apprehensive going in a ship of it's age, but was pleasantly surprised all around. The ship was in very good shape and the recent refit worked well.
So, how do RCL and CCL compare in offerings? First of all, the RCL interior and OV cabins are WAY smaller than Carnival - at least on this ship. My cabin was fine for one person, but with two or three it would have been tight. I think the Cruise Director referred to them as "changing rooms" instead of "state rooms". RCL does not permit any carry on alcohol unlike Carnival - just an annoyance.
Dining - did MyTime on both brands - RCL was better and the waiters (Estelito and Myatori(?)) were great. Carnival made it seem like an after-thought and made no attempt to get you with the same servers each night. Food was pretty equivalent for both. No lobster - but it was a 4 nighter compared with the 7 nighter I did with CCL. More people seemed to respect the "formal" dress on that night which made it seem more elegant.
Activities were somewhat less on this cruise - but we were in ports every day so I didn't expect a lot. The Cruise Director was amazing and made a big difference in the participation level in the various "parties" he organized. Some people tag CCL as the "party cruise line" - but I would have to say the parties on the Majesty were more fun and had greater participation. Embarking and disembarking were about the same and fairly easy. Cabin attendant was attentive but not overtly present.
Overall, I had a wonderful cruise (a person would have to work hard to have a bad one) and would do it again!