Does anyone have any experience with this particular bag? I am looking for a bag that won't really move around during my rides. I also don't like the seatpost velcro closure that my old Jandd pack has.

I was about to jump on this Topeak bag but have read some accounts where the plastic bracket that holds the bag to the seat rails (which is why I was interested in it) has broken after only a short use. So, I though I'd ask you heathens (oops, not the mtb forum), fine ladies and gentlemen, whether you've had any experience with it and if yours broke, too.