Karachi Outpost (S)
You can find it here for $225.
UPDATE 09/25/15: I still wear it for all my photo sessions / client sessions and it's great to be able to fit my equipment :) But I do notice that when I go on my adventures (camping/climbing) basically anything that has to do with me scrambling rocks, I tend to choose a more streamlined backpack that isn't so bulky. I feel a little top-heavy when I have my karachi, which is great when I'm not doing much and just photographing at a park or what not. But not so much when I'm on the side of a mountain looking 100' below me.. Haha! None the less, I am still very impressed with the quality of the materials. I prettyyy much just drop/throw my backpack onto the ground most of the times. That's how much I trust this backpack!
Update 09/23/2017: I am now using a peak design backpack for my photo adventures, click HERE for my review :)
I don't usually write reviews, but it was hard to find any feedback on this particular backpack so I thought I might write one just to help out! Originally, I was deciding between the Langly and the Karachi. But ultimately chose Karachi because of Crumpler's reputation and their fast customer service. It definitely doesn't look as 'classic' or aesthetically pleasing as Langly's Delta bag, but I think the protection of equipment was more worth it with the Outpost. I also wasn't sure the Langly bag would be able to fit my equipment (it looked more like a backpack for small film cameras/ etc).
Aesthetics:
This backpack is so good looking! I wore it all around Europe and wasn't worried about it looking like a camera backpack. The straps were very strong and I had it hanging on a hook a majority of the time (it was quite heavy with all my equipment in it).
Construction:
The construction of the backpack was made with high quality materials, IMO. I was not worried placing it down anywhere along the European streets and the few times I got dirt on it, I just wiped it off easily. It is extremely heavy duty, and I appreciated the rain cover that came with it.