I personally like the Lowepro Flipside, for me, it works as it holds all of my gear. If I need to change a lens, I take my arms out of the staps, while the bottom straps are still connect around my waist I swing the back around and open it up to reveal my gear- it's like having a table top right there. They have a demonstration video on it as well: http://products.lowepro.com/product/...AW,2116,14.htm
Edit: Looks like I'm too late
I'll have to try that swing around option with the (empty...just in case) Guru when it arrives, looks like a great idea.
My gear: Canon 500D, 17-55mm F/2.8 IS, 70-200 F/4L IS, 100mm F/2.8 macro (non-USM), 50mm F/1.4