We took a detour here from visiting El Yunque rainforest. This little strip of food shacks is on the beach (weekends only?) and my goodness the food is delicious and CHEAP! The Bacalao is to die for. Also get the coconut juice they open the coconut right there for you. It was def my best authentic experience. I still crave the food.
Regarding San Juan, Mmm just thinking about eating mallorcas at La Bombonera in San Juan makes my mouth water. Besides that San Juan left much to be desired. The beaches were some of the worst I've been to...and I've been to Galveston!