I've just bought one of these to trek around the Atlas Mountains and Western Sahara. I think you've probably selected the ideal bag. In my case I need to fit in a Canon 5DMk2 with 24-70L attached, and this is quite long at about 20cm. I discovered that the padded camera box in the bag just about accommodates this with the lens hood reversed and quick release mount attached. The top zip is then quite tight, but do-able. In the smaller partition of the box I then still have room for my 24L lens and maybe a remote or something. There are an additional 3 internal pouches, one of which can accommodate my iPhone and the other two 5D2 batteries or CF cards, etc. This then leaves the bulk of the internal cavity empty into which I've put my big fleece jacket for cold desert nights! You could also have food, creams, provisions or more camera stuff if you like. On the outside of the bag are big pockets for maps, wipes, or whatever. These are not zippered or even sealable with Velcro or anything so you take a risk with these, although one would be hidden next to the wearer's side. The bottled water pouch at the front seems perfectly positioned too. All in all, this seems to be the near perfect bag for someone travelling light who needs to carry a professional camera, but also needs to pack some essential provisions and not look conspicuous. It allows you to wear it across the body and reach in to grab the camera quickly with one hand without having to stop, remove the bag, find somewhere to place it, take out the camera and then put the bag back on – not my idea of fun when on the move. The drawbacks I can see is that there is no tripod/monopod hook or anything, and the outside pockets and not protected from pick-pocketers! The pluses outweigh these though. None of the other bags in the thread allow you to pack so much non-camera stuff. Fine if you're on a day trip in an urban environment and can get access to shops and cafes for stuff, but if you’re genuinely out trekking you really need ‘more bag’!
Anyway, I’m going on Thursday, so when I return I’ll be able to provide a real-world verdict.