My husband has this. His collar bones are fairly prominent, and no amount of adjustment seems to alleviate the discomfort longer than a couple of days on the trail. He's tried several different packs. His base weight is about 15 lbs, highest pack weight with full supply of consumables and/or 2 days of water (we are in Texas) about 35. On trips he ends up stuffing his spare socks between the straps and his collarbones. This seems to work but it's a hassle because he's always having to re-settle the socks in the right place. For this summer's trip I am going to make pads from some old wool socks and sew them permanently around his shoulder straps.