Never stayed at Banyan Bay, but I've run past there in the mornings and it always seemed really pleasant. I ate at their restaurant a couple of times also and they had great ceviche and good burgers. I'd water taxi to Caye Caulker and air taxi it everywhere else. Get a golf cart for a day and try new restaurants, but also take a day to walk around and get to know the hidden spots. You'll find them by foot. Have a great vacation, I'm on my way back to San Pedro in 2 weeks, just love the place.