Pretty sure Brandon has been to Costa Rica a few times, I think his brother lives there or something. Not sure if he's ridden there, but I would hit him up.
Where in Costa Rica you headed? There was a place in Guanacaste I checked out a couple years ago.
Here's their site, looks like they've expanded the trail network since I was there. I'd go early if possible, it gets really hot! Everything seemed well maintained. Nice trails and scenery...though I tend to enjoy anything that's not rocky and technical just because it's a change of pace. http://www.puravidaride.com/mountain-bike