We are E+ /D+ on these two lines so we sail each of them often. We like to switch it up too. We sailed a lot recently in The Retreat on Celebrity but then they started messing with it, raising prices dramatically and cutting services and suite amenities. So we strayed! We did O-Class this year (Symphony) on RCCL and very much enjoyed the CL suite we had. The ship is huge but has everything imaginable. Entertainment far better than Celebrity. Loads of restaurants and bars. Yes more kids, noise, and less of a serene experience but we don't mind that on occasion. Service and staff were outstanding. We did not do the MDR but mostly Coastal Kitchen and specialty restaurants (Hooked, Jamie's, Wonderland).