We are platinum on DCL and Select on Celebrity, and sailed Harmony of the Seas B2B in July. Here's my mini-review:
Food & drinks:
We were not impressed with the Windjammer buffet - there's no outdoor seating, the serving areas seemed cramped, and the food was okay, but not great. I would say we prefer DCL/Celebrity for the buffet than RCL. We did enjoy the Solarium Bistro was very good for breakfast. The MDR was fine. The specialty dining was good - better quality food than the MDR - but not worth the premium. We did enjoy the Schooner Bar, where my college-age daughter got the bartenders to mix her custom mocktails, and Sorrento's pizza on the Promenade. We had the Ultimate Dining package and Refreshment package on one cruise, and neither on the other, so we did pay out of pocket for alcoholic drinks and drink prices seem higher than DCL. Drink packages seemed to be priced higher than on Celebrity as well, hence not purchasing alcoholic packages, and did not spend even half of one package on drinks for 2 of us.
Spaces & Events:
Our sailings were at or over capacity, and we found that while HotS does absorb the crowds well, it was just not the right ship class for us. There were a lot of tiny venues that when they had events ended up overcrowded - we attended Disney Music Trivia, which was in such a small venue that there were teams sitting on the floor and spilling out into the Promenade. The schedule of events seemed haphazard and not well planned, with either nothing scheduled, or multiple overlapping events geared towards the same demographic. It felt to us that RCL expected everyone on the ship to be spending their time on the pool deck utilizing those amenities (pools, flowrider, slides, rock wall, etc.) in general, so other events were limited in space and schedule. Arts & Crafts events had limits of 15-25 participants on a 6000 passenger ship. After sailing DCL and X, we found the lack of live music in multiple venues... odd. There was music on the schedule, but we're used to both other lines having frequent random music in the atrium, or a lounge you can go listen to music in during the day - there was none of that on RCL. The travelling pianist was cool - especially when he was in the elevator - but otherwise you had to go hunt for the music, it didn't really find you. The Ice Shows were good, Grease was okay (cast was great), but having to both schedule shows on the app and not have mainstage shows every day was also odd. We did see the Aqua show 3 times as they only had one show running, and it was entertaining. I would rate DCL and X both above RCL in general daytime/event entertainment, but they're probably all about equivalent in main stage/headliner entertainment.
Stateroom:
We had both an Oceanview verandah with a larger veranda and a Central Park verandah. The OV was great - plenty of space for the 3 of us on the balcony to enjoy the views and the sea. The staterooms were fine for 3 people - we had no issues with storage or bathroom sharing. The interiors of both rooms were pretty much identical, though the CP balcony was connecting, and we could hear our neighbors very well. We did enjoy the live music in Central Park from our CP balcony, but found that we had minor issues with not being able to see the horizon that we never had with previous inside staterooms, probably due to the lack of visibility of the motion of the ship. Even with a single bathroom, I think the layout of the RCL ships were good for the 3 of us in a room, but the couch-turned-bed was never returned to a couch while we were there (staffing? Maybe that's normal?). I'd say RCL and X are similar in balcony stateroom ratings, with DCL having a slight edge due to the split bath and the curtain between the spaces.
Staff:
The staff was great, but there are a *lot* of people on Oasis class ships, and unless you find one bar or space to frequent, they don't really know you. On both X and DCL we would see our servers and bar staff frequently, and they would learn who we are, what our preferences are, and often find us and offer those to us. On RCL, we had to go order at a bar more often than not as it was obvious they were understaffed - bar managers were working the pool bar on a regular basis. The staff was friendly and helpful, but just obviously busy. We also found the lack of places to set glasses/plates/etc. on the pool deck just... weird. DCL has obvious areas to bus your tables to. RCL doesn't really have that - and often not enough staff to clean up after people either. We have found similar issues on X, but the staff there seemed more on top of cleaning the pool deck.
Summary:
We really enjoyed the itineraries we sailed on RCL, and Cocoa Cay is a great private island, but we enjoyed Labadee more as it had a bit more of a
Castaway Cay feel (less nickel-and-dimed). We would sail RCL again, especially an itinerary with both Cocoa Cay and Labadee, but not on an Oasis-class ship, and not until we are Elite on Celebrity so we get Diamond perks on RCL. We found we do enjoy DCL and Celebrity more, but we were glad we tried the ship. It was fun - we had a great time and enjoyed the ship and had a great vacation, but just found this particular class of ship isn't for us and the way we cruise. It was a different kind of cruising (in my opinion) from DCL, which isn't bad, but wasn't what we expected and didn't really fit well into our cruising preferences. It looks like the smaller ships on RCL are more like what we're used to, so I look forward to trying those in the future.