In Peru I used both llamas and burrows to haul my gear into various camps. I never understood the use of llamas. They carry half as much, walk half as slow, require constant proding and cost twice as much! WTF! Then talk about trying to get a load on their back, that was the most dangerous part of the trip.
It's always seemed like a great idea for the Pasayten or Wind Rivers but the cost is probably untenably high for people use to doing it on the cheap. It's gotta be what? at least $100 a day a guide, $50 a day an animal. So $300 to get your shit in there and then how are you going to get it back out!?
Be cool to hear more first hand experiences.