I got one of these a few weeks ago to replace my old wingnut pack. It is very comfortable to wear and the harness really does work. Most of the load is carried on the hips and not the shoulders. I put it on and forget its there. I'm 6'5" 210lbs.

I got it from Competitve Cyclist, for $69 down from $150. Actually, I got it a little cheaper as I had a coupon code lol.