Actually, I've had trouble understanding a few of Delta's Hispanic reps (cordless phone near the PC probably didn't help, either).

I don't think I've ever had a call routed to DL's Indian call center. I wonder if the time of day makes a difference. Whenever I can, I try to make reservations early in the morning (US Eastern Time), and, if possible, on weekends. I once called SMS at 6am on the 4th of July and got a rep with NO time on hold.