Although I had been on a couple of cruises many years ago, this was the first for my wife and two daughters. We also brought my mother-in-law along. It could not have turned out better.
The ship was beautiful and there were many things to do and see. It was large enough to have lots to do, but not so large that it was overwhelming. The outdoor orientation of the Radiance class (many spaces are designed to be wide open and have views of the sea) was very nice. The staterooms (we had balcony rooms on decks 8 and 9) were reasonably sized and well taken care of. The food was very good in the regular dining rooms. We had a couple meals in the specialty places, and I think it was nice to do that because it felt like a special occasion, but it was really not necessary to do so for the food, as the food in the regular places was quite good. Service was excellent throughout the ship. The entertainment was very good. The fitness center was very nice, with excellent views - I was there every day at least once a day - though it could get crowded, I never had trouble getting on equipment. The ship felt safe enough that we were able to let our 8 and 11 year old daughters move around relatively freely, which made things much easier for us than many other vacations. My main suggestion would be that it would be good if the guest services people had a clearer idea of what was going on - they seemed fairly confused about things like arrival times and how the tenders would work. We eventually got the information we needed - but the activities people ended up being more reliable than guest services. Speaking of the activities people - they are amazing - unlimited energy, creativity and patience. I don't know how they do it!
Bottom line, after this experience, my family is looking forward to going on another cruise some day, and would definitely lean toward Royal Caribbean.