Yes, I was at the one in San Pedro. Just call ahead if you want to guarantee a jazz experience--one of the nights I went, it was belly-dancing music and exhibition. Big fun in its own way but not jazz. I believe what's happening there is listed in
www.ticotimes.net. Another thing I wanted to try was seeing if there is anything like a jazz studies department at the Univ. of CR or another local school. I believe the Escazu club was purpose-built and is newer but never made it out there. You'll have a good time whichever location you choose, no doubt. Lotsa locals of all ages, if memory serves me right.