In all honesty, the cabins are not luxurious, but they are fine for two nights if expectations are in line. There may still be a degree of cruise ship luxury, but mainly in the dining room and not the cabins.
Bathrooms are small, not at all fancy, yet functional. I had been warned about the small showers, but our shower on Diamond Princess wasn't any larger. There were a few dings in the furniture, although I've seen that on newer ships, too. Beds, however, were very comfortable. And, we had more storage space than needed. We were in U44 on Upper Deck.Definitely go for the higher cabin categories, and try to stay on Upper Deck or above.
We had no AC problems that I recall, and we went during the month of August. Of course, systems may temporarily break down on any ship, including brand new ones.
Food was fabulous when we went. But being an older ship, there are limitations. The buffet area is small, and the seating for it is near the pool. At the time, there was very limited room service, as well -- pretty much finger sandwiches. However, the dining room is amazing. The decor is lovely and there are large windows. And, I'd rate the service about the best of any of our 20+ cruises.
While it won't feel like an average cruise, I agree with Raoul that it is an opportunity to sail on a true ocean liner. Besides, much of the time will be spent in Nassau, so there will be plenty to do ashore.