I can usually tell. As soon as they say their name and "How can I help you?" I kind of know whether they are going to capable of booking a complex award itinerary without taking an hour to do it.

Slow talkers are bad. Mumblers are bad. Accents are bad, except I've had very good luck with agents from the Philippines.

Sometimes I think about just cutting my losses and hanging up as soon as they say thier name and and calling back, but I don't want to be rude. So I go ahead and try to arrange the ticket, giving them the first segment. They search for availability. A minute goes by. I want to hang up. Two minutes. All the while I know I'm just getting deeper and deeper into the morass.