the internet wouldn't be any good without people like you rwan.

i have had a large timbuk2 for many many years. i really find is that if you *really* adjust it each time it won't slip (when it's mostly empty the right side is all the way into my armpit), and it's not at all uncomfortable that way. it tends to rotate out to the right unless it's cinched down. the only occasional beef is that when it's tight like that and i unclip the keeper strap and rotate the bag around my body the edge of the mainstrap sometimes cuts into my neck. but still, i've worn this bag daily for years and years and i've no complaints. oh and hey i'm not a messenger.