I just had a very positive experience with Lowepro customer service.
My Slingshot 100AW bag, which I like very much, developed a frayed, failing seam at the strap attachment.
I emailed Lowepro customer service on the weekend and they responded on Monday. They requested a few details and immediately arranged to FedEx a replacement bag (actually, an upgrade to the newer 102AW.)
It arrived today, Thursday.
Absolutely first class customer service, and they stand behind their warranty.
Lowepro will be the first place I look next time I need another bag.