Overall, we had a wonderful time on the Oasis of the Seas. We had previously sailed on Radiance and Freedom class ships, which we liked, but the Oasis blew them out of the water (so to speak!). Here is some detailed feedback:
Ship - the ship overall was very clean, though it did show its age in a few places. However, everything worked fine and the "small wonders" were a lot of fun to find all over the ship.
Cabin - reasonable size balcony cabin, with a surprising amount of storage space. With two people in the cabin we never felt crowded. The balcony was a little small, though we knew it was only 50 square feet, but we would have liked having a lounge chair instead of the two regular chairs.
Nice cabin towards the middle of the ship, not near any of the noisy areas.