I want to write positive reviews but in this case my review is more pessimistic but hopefully will help you make an informed choice on whether to sail with Royal Caribbean or not.
The good: they have a special service offering for repeat customers. If get to the upper tiers of their rewards program, you will have access to priority check-in, access to welcome back parties and if you are a diamond, emerald or pinnacle members you have access to gifts and diamond lounges. However you would have to sail I think 43 nights to get to even platinum. I was able to get to gold due to their alliance with MLife (from MGM in Las Legas) so had some sort of recognition without even sailing with them.
They are bring out brand new ships but this may not affect the service levels (see below).
The bad: 1. The boat that I cruised on was old and tired and the shower temperature control did not work so there was only one temperature which was a little bit too warm, especially for a very hot day in Australia.
2. The service was lacking. If I did this cruise again, I will opt to give tips directly to those who made more of an effort rather than pre-paying gratuities. It would probably incentivise the staff more.
3. Be careful of the used by date of their food. We noticed that the yogurt was 8 days past the "best before" date and just wanted to bring this to food and beverage manager's attention. Her response was that it was international law that allows them to serve food that was within 2 months of the "best before" date. Really? For yogurt too?
4. The food was mediocre at best. I am not a food snob but felt that they really did not bring a standard that you would expect from this type of cruise line. I resorted to paying for their premium/specialty restaurants and found this to be much better. Get the 5 pack deal as it costs $20 USD per head which was not too bad considering that We had $300 on board credit.
5. The onboard entertainment was boring. I have sailed on Carnival cruises for my first and other time and found their shows to be of the same standard as what you see on say Broadway... almost.
I think I will sail with another cruise line next time.