So I have never done one of these before because there are always hundreds of reviews already, but since this ship is only a couple weeks old, I figured I would chime in.
Cruised with my wife and daughter 20 and son 16. We have cruised together at least 5 times and my wife and I an additional 2-3 times. We have done Oasis of the Seas, a couple other RC ships, Disney Magic, and a Carnival cruise or two.
Overall the ship was great to excellent. We sailed on 12/21 which was the second full week. I was somewhat concerned about the new ship, new crew, new situation, but honestly if I didn't know going in it was the second cruise, I would have had no idea.
Cabins were small in my opinion and the balcony was small. Now there is a chance if you gave me the square footage of the cabins I have had, I would not be surprised if it was pretty close to others, but it felt small. A little more squeezing past the end of the bed to get to the balcony, squeezing out the door to get to the hallway, it just seemed that things were cramped. Balcony had a table and chairs and they seemed kind of "fit in" to the space that was there. We also had an inside cabin that seemed a little small as well. We were on deck 9 towards the back which is a great spot for access to the Lido Marketplace and the back pool deck.
Cabin service was good. Things were clean. I did find it interesting that the cabin steward asked us early on when he should come in for the day and he came in one time. In the past it seems that every time you left, the dude came in like a ninja and folded towels and stuff, This time, he kind of came in once a day, Maybe once at night a couple times, but you didn't get the feeling where the guy was always around waiting to jump in when you left. Room was clean and that was totally fine with me, but something I noticed.