Upload & Sell: Off
I have an older Airport Addicted, which is similar, but without the wheels.
The trick to efficient space utilization is to figure out how best to use the deeper (8") portion of the bag. If you have a 400/2.8 the lens hood is really large diameter and this will take some priority for this deeper space. I use the 8" deep space for my 70-200/2.8 IS which is stored vertically, lens cap straight downwards with the bag open and hood reversed. The lens is 8" long so this works out well.
I also store my 5DII with L bracket and handstrap with the left side of the camera down (handstrap up). 24-70/2.8 lens attached with hood attached (not reversed). This facilitates the quickest access to shooting; grab the handstrap side of the camera while in the bag, lift straight out, lens cap off and start shooting. My flash is also 8" long so it goes here.
Think Tank used to have more user pics of packing arrangements, but the revised web site has done away with most of these.