Departure times may be brutal (like SCL and JFK) but the upside is that connections in PTY are always a snap. Just try to make a 30 min. int'l to int'l connection in any CO hub!!
In PTY, you'll either have 1 hour, 9 daytime hours, or 15 overnight hours. In any case, it's enough to get from 1 flight to another, have enough time to day-trip into the city, or comfortably get a good night's sleep at a hotel.
COPA availability does seem to be much better than CO-- and note that now with Sky Team, you can use AM to cross the US-Mexico border. Once you cross that availability barrier, you're really home free with finding seats.
IMHO, COPA may be a stepchild, but it's one of the more useful ones.