We had a balcony cabin on deck 6. The room was a reasonable size, perfect temperature, our little balcony was worth the extra, and the stewards kept it looking perfect.
We assumed that the soundproofing in the rooms was good as we had unbroken sleep every night in the first week. Looking back, the soundproofing was the same as any other ship we've been on, we were just very lucky had quiet neighbours who didn't make much noise at all. It was bliss and we felt relaxed. The second week was very different though.
After changeover day, we had new next door neighbours. A younger couple, they woke us every night on their way back to their room in the early hours, loudly banging about, arguing, moving furniture and fighting. Sunny afternoons on the balcony went downhill too. The balconies are separated by hinged plastic screens with a gap at the bottom big enough to let all of our neighbour's body hair clippings blow through to us when he emptied out his daily shavings. All to loud music - and the odd bit of abuse shouted at his wife/girlfriend.
Compact but adequate. Perfect temperature, but had a thermostat too. Very comfortable and large bed. Two power points. Lots of luggage room and storage. Soundproofing could be improved. The sliding patio window opens out to a small balcony with enough room for only two chairs (not reclining) and a table. The furniture on the balcony is not plastic and is quite sturdy.