Enjoyed birding in Costa Rica but quetzels zero for me. No experience of Panama.
Birders might like to consider lower Rio Grande Valley - it was suggested to me by a Senior couple I met at the Carden alvar (Kirkfield.) They lecture on the birds in Rio area in the Winter. As I have a little grandaughter outside Austin I flew down early in Dec. to deliver presents and spent a few days further South in the McAllen/Mission area. Sadly too late to see the painted bunting, (my g'daughter had seen one on her birdbath at Thanksgiving.) Note: while at her house I did see the white collared seed-eater.
Highlights of McAllen/Mission area:
Bentsen-Rio Grande Valley State Park. (Here I purchased Kaufman's BIRDS of North America as my usual handbook did not cover this neck of the woods adequately.) Park guide took us out from 8:30 to 10am (glad to be in a van as it was COLD!)
Saw gorgeous greenjays, chachalacas, 2 clay-coloured robins (RARE). Doves:Inca, white-tipped and white winged, also common ground. Black and white warbler. Sparrows: Lincolns and swamp. Gt. kiskadees. Also javelinas.
Santa Ana Nat. Wildlife Refuge:
High tower takes one above the tree canopy: numerous Couch's kingbirds. Goldenfronted woodpeckers. At the ponds: cinnamon and blue winged teal; pintail and black bellied whistling ducks. Cattle egret, stilts. Interesting here that the kiskadees catching flies over the water seemed quite excited and were 'flaring' their yellow crown patches. Could be seen with naked eye. (Kaufman does not illustrate this but I've seen it on web re: Peterson - I don't have his book.) Park guide said it was not sexual behaviour.