Hi. Im so happy that I thought I should share my experiences with you guys.
Ive been pro working with my linhof technikardan for years and always used a Lowepro magnum AW bag (i still love it). I Usually thought that was the only one that suited my camera, and was able to handle 13 film boxes +3 lenses and a lot of other stuff (as usual).
But now Ive seen the light. I got a Billigham 550 with backpack straps mounted to it. Its perfect, I can even bring 1 extra bellow and still have room left for a thermos. Also the massive amount of pockets all around is a blessing.
Anyway I just wanted to recommend it if you need a good solid bag with backpack capabilities for a lf camera. I did however have to sew two inserts together to get a long one for the camera, but that was quickly made.
The only downside I can see is that its probably not so waterproof, but Im thinking of treating it with some greenlandwax...