I've purchased from GPS Travel Maps, the map of Costa-Rica.
I'm using Garmin Nuvi 3790.
After two weeks in Costa Rica, I can tell you all, the map from GPSTravelMaps, is very incorrect. They are missing major roads, even roads that exists at least 4 years before my purchase date (Feb-2011).
We've spend huge amount of time (and fuel) due to this wrong map.
On my return back home, I wrote to GPSTravelMaps - but no answer any more ...