That is right up the alley of what I am looking for, those Sac things all looked empty, none look like they have even a body in them never mind a body and three or four lens's. I am glad your happy with it, but looks to delicate. And appear they would put strain on your shoulder and even cut in.I heard about this backpack, the Rotation 360; it looks pretty neat, I'm thinking about getting it:
http://www.rotation360.com/
Click on "Features" and go through the product shots.