Angled straps are definitely great when wearing the bag high, (as any messenger bag really should be worn under load). However, I don't have the issue you described with my Timbuk2 Classic large. In fact one of the things I like about the bag is that it conforms to the shape of my back regardless of how much is in the bag. I don't like to wear my bag low, however, specially if I am carrying heavy items. The strap doesn't sit properly across my chest/shoulder and the bag impedes my ability to walk or ride comfortably. High and snug is the way to go.