Autobytel - Anybody buy a car with it?

I'm in the market for a used car. Something along the lines of an 02 maxima (with a 6 speed). Anyway, I checked the inventory at autobytel's website and they have a bunch near me. The question is, what is the incentive to use this service rather than buying the car directly from the seller. I know they offer a 72 hour grace period where you can decide to keep the car or send it back. But what is the fine print? Is there any kind of warranty attached to the deal, beyond the 72 hours? What if something goes wrong after that period? Does it have to be repaired by the original seller?

The reason I'm asking is that one of the dealer's listed with a 6 speed, is about 100 miles away from where I live and I don't want to risk sending a potentially troublesome car back and forth to their shop. Do they let you take it to your own local mechanic and reimburse you for it?

So, anybody buy a car this way? Were you happy with the car? Were you happy with the service? Would you buy through them again?

Thanks in advance...