First, let me say that I consider myself a "seasoned cruiser," with six cruises--between Princess,Carnival, and now Royal caribbean. In fairness, it's been about 15 years since the princess cruise and I don't remember enough for a comparison. However, my husband and I have cruised several times with Carnival and felt that we wanted to try RC because of the extra activities on the ship and the good reviews.
Embarkation: The processes of embarking was similar to Carnival. We were late arriving. Agents were generally pleasant but the process was a bit slow; it helped that we were the last one's boarding.
Staff: All staff was very friendly, attentive, and willing to help. Exceptional service.
Room: we were in a balcony cabin 7352. Our room was always cleaned twice a day; no complaints. I heard that the rooms were very small, but we were surprised that our room did not seem much smaller than the balcony cabin on carnival.
Ship: The ship itself was beautiful and much cleaner in most places (such as, buffet dining room=the windjammer)than carnival. The buffet was kept clean always and fully stocked with food. The shows were just OK to us; we liked the carnival shows better. The ship had only one production show for the 7 day cruise, but had other shows---such as a magician and the "coasters" from the 60's (I think).
The main difference is that we felt there was alot of "down town" in between events; whereas, on carnival there was always something to do if you wanted. On RC, many of the activities required an additional fee, including the extra restaurants, such as Johnny rockets and Ben & Jerry's. Bingo was super expensive ($32 for four games),so we only played once (and lost). RC people generally observed formal night; most people had long gowns/suits/tuxedos, very different from the more casual dining room attire of Carnival. Added features of ice saking rink, rock climbing wall, and flow rider was great. However, most had long lines.
It was an older crowd mostly; I'd say 55-60% over the age of 49. RC did not have the "energy" and excitement level that Carnival had. I would definitely cruise RC again when I want rest and a quieter atmosphere. It was definitely a much nicer ship. However, if you're looking for high energy and want to stay busy (or at least have many choices of things to do), I would recommend Carnival.