Let me get the negatives out of the way first. The decor of the cabins is incredibly bad and old fashioned. How on earth can you build a new state of the art vessel with such old-fashioned and downright ugly standard cabins? What did the think? If you have a cabin with bed by the cabinet/wardrobe, then your cabin looks also very small. It´s much better if your bed is by the window. The bed is very comfy though.
The Sauna and Spa. Again, what did they think? In times, where all new cruise ships feature bigger and better spas and saunas, Oasis class has a little hidden something inside the ship, which does not earn the word Spa. Offered at a price where most people say "No" without regrets. The price is ridiculous and the space used is a joke. That was my biggest disappointment on the ship! No free sauna? What is it with that? Cheap.
Now the positives: Never, and I literally mean that, never a cue or line. Even at guest relations they managed to work the lines fast, due to having staff available before the desk, asking people in line already for their requests and issues. Kudos!
Getting on and off the ship has never on all my cruises been faster. Food was mostly good, except for Windjammer, but there are so many other choices that this did not matter. Still, RCL needs to change menus for the main dining room urgently. Most menus and items are 6 plus years old. Especially good the food at the Solarium. Healthier and light, just what most people like these days.
The Suites are great in both decor and space. 3 Lounges, one for the high end Suites and top tier guest (Pinnacle), one for the regular high end suites GS and up to OS incl D+ members (Concierge Lounge) and one diamond lounge with nice views and outside sitting overlooking the promenade. Staff outstanding throughout the ship.
The shows were great, especially Blue Planet. Most shows we saw where specially hired for our cruise by Atlantis. They were all outstanding and cannot be compared to what regular cruisers see on RCL. Much fun. Both cruise directors, yes we had two, one from Atlantis (Malcolm) and the regular one from the Allure were outstanding and incredibly good together.
The positives outweigh the negatives by far but still. There is room for improvement. Overall a great week on a great ship.
Would I go on the Oasis class again? No, not on a regular cruise. Heard today, that the new ship generation called Sunshine will not be, what I hoped it would be, nested somewhere between Freedom and Radiance Class. Instead it will be of a size, somewhere between Freedom and Oasis Class with over 4000 passengers. I was hoping for a rather "Solstice Class" size , RCI style. That is a bit too big for my taste, to be honest, but I guess the right size for RCI to make money and offer all the new features thew want to offer.