I agree the La Piazetta is a must do restaurant. Also try a place commonly known as 70 pesos all you can eat. Very good BBQ.
Ride the local bus system instead of using
taxis. It is efficient, cheap, and the locals are great people.
My wife and I went to
Nuevo Vallarta in late June and are returning to PV in March but are staying at the Sheraton. I was not impressed with Nuevo as we were way out of town with little/nothing to do. I guess if you want to stay at the resort itis O.K. but otherwise too far out. The Sheraton is a great choice as it is outside of the noisy/party area but a close walk, bus ride, taxi ride to the hot spots.