My first cruise on RCCL was long ago (1975) when RCCL only had three small ships - The Song of Norway, The Nordic Prince and The Sun Viking. My two week cruise on the Nordic Prince was top notch and one of my favorite cruises of all time. My second cruise on RCCL was on the Adventure of the Seas in September of 2006 and I enjoyed it very much - though I did feel it was not up to the level of several other cruise lines I had been on in the two years prior to my trip on the Adventure. Many things that other cruise lines (like Princess) have included in the cruise are either extra charge on RCCL or non-existent.
This was one of my most disappointing cruises - only my one and only cruise on Carnival many years ago was a worse experience.
I had several issues with the Brilliance - they changed my room at the very last minute due to an issue with the stateroom - without giving me advance warning so my luggage tags could be corrected - and they did nothing to alert the baggage handling staff even though I was the only passenger that had a room change. As a result, one of my bags showed up 3 hours after embarkation and the other took an additional two hours because they didn't know where it was. Someone evidently finally located the bag and brought it to my cabin.
The food was mediocre at best and many items normally on a cruise ship menu were never served in 9 nights - like lobster. The buffet food was no where near the quality level of Princess and the buffet is not open 24 hours like Princess.
On three separate occasions I had to go to the main desk to complain about noisy maintenance work being performed after 12:00 midnight.
Due to the issues, the guest relations officer asked me to come to her office so I could summarize the problems I had during the cruise. For the most part, the reaction was that the food quality, menu and service are different in Europe - the cruise line can't get the same quality provisions they get in the US so they have cut back. I'm not sure if it's a quality concern or more economics.
To sum it up, the Brilliance was no where near the quality of the Adventure of the seas and was not even comparable to either the Diamond Princess or the Caribbean Princess on Princess Cruises.
I will think twice about booking on Royal Caribbean again.