The service at Bahia Principe was outstanding. The hotel rooms have been neglected, but all the problems I encountered were resolved by the Don Pablo Collection Manager or her staff. If you go, certainly upgrade to the Don Pablo - it's worth every penny for their services alone. You also get access to pool and beach areas that are not as crowded and have bar service.
The vegetarian food was ok and they made every effort to accommodate my tastes. The wine selection could use serious improvement - the "premium" wine selection was poor and tended to be served hot. Since DP allows you unlimited a la carte access, get reservations at the Don Pablo restaurant as often as possible - definitely the best food at the resort.
The diving is really good - much better than I had been lead to believe was possible in Jamaica. There are no big fish and you'll see fish traps on the reef. Overall, it was well worth going and the dive operation was solid.
As a single woman traveling alone, I felt very safe here.