We rented a house in Heredia my first trip. There's nothing going on there whatsoever from what we saw, but honestly, we didn't waste much time looking. We just drove into SJ and visited "sure-thing" places. It's probably a good idea to have a rental car if you plan on going into the city every day. We took a cab once, and the metered fare was almost $10 one way. But it depends where in Heredia you will be, I think we were pretty far out of the city. I think part of the reason the fare was high was that the cabbie sensed 2 newbies and got "lost". But then karma stepped in and and he got pulled over by the cops for an illegal turn and had to pay the guy off, so I'm pretty sure the prick lost money by driving us.
Never again will I stay there or recommend Heredia to anybody!!!