me? no, never!

my timbuk2 was crap and wore out in less than a season.
my crumpler was not-quite-waterproof
bailey was a jerk to me
dank doesn't exist any more
the pac's are great, but the x strap gives you, well, superboobs.
and chrome doesn't custom stitch.

i got an under the weather, and i love it.

i think the important thing here is the width of your shoulders. make sure that the bag you get rides as small as you are. some of the bigger bags, especially when empty, will be larger than you are at their smallest setting. the kremlin (chrome) i won slipped off when the strap was all the way in, just because the bag size alone was bigger than I am.
most bags won't slip down/around, though. it's cuz they're meant for you to be leaned over your bike, carring part of the load on your back and the rest on the strap.

i'm happy to answer questions. i've won a couple chromes, a timbuk2, a dank, and a crumpler this year, and have tried on coworkers' pacs, reloads, and baileys and that's how i have good comparison.