We just got back from Rincon, and stayed with Marc at the Blue Boy. With the schedule at Taino Divers, we didn't have time in the morning to really appreciate the breakfast (Marc makes great crepes and French Toast, plus a veggie omelette), so we usually opted for cereal, toast, and some fruit. The pool is fantastic, and a great place to relax after a dive. We were there in low season (May), and for three of the four days we were there, it was just us, Marc and Paco (his new kitty). We rented a car in San Juan, so mobility wasn't a problem, and some of the better places to eat are not right in town, so being able to navigate is highly recommended. If you are going all the way to Puerto Rico from the States, I would also strongly suggest that you run down to La Paguera and dive the wall. We spent one day with West Divers there, and are already planning a return trip next year.
Plus, plan to spend a couple of days in Old San Juan, either on your way in, or out. We stayed at the El Convento, and it was just mystical. One caution, though, you will not need a car in Old San Juan, so plan on either getting it on the way to Rincon, or ditching it when you get back.
I can provide more details if you need them, just send me a PM, and I would be glad to elaborate.
Cheers!