I'm in Apaneca El Salvador right now. The worst hassle was definitely crossing the border into El Salvador, but even that wasn't a big deal - it took almost 2 hours to fill out all the paperwork to bring the truck in, but it only cost $5.
The best surfing of the trip has hands down been El Salvador. The coast west of La Libertad is break after break of perfect waves. There are some crowds, but people are friendly and localism is confined to a few waves so it is manageable. It would be a wonderful week trip to fly to San Salvador, take a bus to Playa El Tunco, and surf your ass off. We also surfed Sipacate in Guatemala which was an ok beach break, but the place creeped us out. There was absolutely no one else there, and at night the "hotel" staff vanished and armed guards patrolled the area. We layed in bed staring at the ceiling during what sounded for all the world like a 2 hour gunfight, though in retrospect it was probably mostly firecrackers and a few people plinking away at cans on the beach.
By far the best day of the trip for me was in Iztapa Guatemala. We caught 6 sailfish on conventional tackle, and then I caught 2 more on a fly rod. Nothing has prepared me for what that would be like. Watching these huge beautiful fish launch out of the water like a rocket is amazing.