I think there is always a risk with print exchanges. I've participated in two group exchanges, one with three other people, and one with four other folks, two blind exchanges, and a couple of private exchanges... for, I think, a total of twelve exchanges. Out of that twelve, I've been 'stiffed' once. I figure, that's not bad. Is this really THAT big a problem? Well, I'll grant you, it may be for the coordinator... and a BIG thank you to those who have coordinated the exchanges.
I find the benefit of seeing others' prints far outweighs the risk of getting stiffed, and unless it becomes a rampant problem, APUGGERs should 'police' themselves. All that said, I will probably be a little late with the next group exchange myself (summer schedules being what they are!) DOH!!!!