I took my fourth cruise, first with Princess, on the Golden Princess-- from San Jan visiting St. Thomas, St. Kitts, Grenada, Isla Margarita, & Aruba. My boyfriend and I are type A 20-somethings from NY and LA (respectively) who are used to travelling in luxury resorts and being surrounded by competent people-- so we may be slightly more demanding than the average cruiser.
Overall, the trip was a fantastic experience and I would like to start by saying that our trip was greatly enhanced by all of the information we received from previous cruisers on this site. The things I felt were most helpful were as follows: first, the recommendation of tipping your cabin steward and getting a mattress pad as quickly as possible-- the beds are somewhat hard (and I like a firm bed) but I had no other complaints or soreness. Secondly, being on the Aloha or Baja deck is critical to having privacy on your balcony. Aloha (where we were) is directly underneath the Lido deck-- which miraculously, we could not hear any noises from at any time of day.
From our balcony, we could not see the balconies directly below us (Baja), however I could see about 4 or 5 rooms on what I believe was the Caribe or Dolphin Deck and as many as 8 on the Emerald Deck. I would be particularly cautious about the balcony rooms 1 deck above the promenade deck, as at times the promenade deck goes up stairs and walks directly by.