I've used Copa to Santiago, Chile. The reason for the fare differential is that Copa's 1st class is equivalent to domestic 1st, not Int'l Business First. Aside from that, the planes are new, the staff excellent, and the food decent. Copa's hub in Panama City is crowded, but very easy to navigate and there's a PC. The Duty Free in Panama City is nowhere as good as it is in Buenos Aries or Santiago. Copa has an excellent on-time record. My only gripe is the flight from Santiago departs at 3:45 ! a.m.