The Brilliance of the Seas is an older ship but is well maintained. There are plenty of public areas so that the ship does not seem crowded (other than the Windjammer Cafe - more on that later). Compared to my most recent Cunard cruise, I can say that RCCL is much more casual. There were 2 formal nights but cocktail dresses or pants with sparkly tops were the preferred attire for women, rather than long formal gowns. Otherwise dress on the ship was very casual, jeans are fine.
The food in the main dining room is good - not great. Some meals were better than others. Our assigned dining room wait staff at dinner were quite excellent, but when seated elsewhere at breakfast or lunch, service could vary. The worst dining experience was at the Windjammer Cafe on deck 11. In poor weather when everyone wants to eat inside, there aren't enough tables/chairs and the room layout can make it quite crowded. There were constant announcements for people to kindly eat and move on so as to make room for other people to eat. Not a relaxing experience!
Hopefully you can get an extremely good cabin rate, as it will be the only bargain of the cruise. Expect to pay a lot of extra fees for sodas, specialty coffees, fresh squeezed juice, of course cocktails and wine. Spa services are not cheap but are quite good - note that gratuities are automatically added on to all services in the spa as well as the dining room. Someone at our table purchased a cookbook (only available through the dining room wait staff) and had 15% gratuity tacked on. Some activities will cost extra too. There is Internet and WiFi available if you want to pay a high price for it.
The Port Destination lecture was laughable - very little port information and mostly a sales pitch on the shore excursions offered by the ship. In fact, the constant sales pitches for various things got quite irritating by week's end.
Other than that, the ship's crew and service staff provided excellent service, and there are enough activities during the day to keep everyone happy. The cruise was a good way to see the fjords; the Geiranger was especially gorgeous.