Summary: I use this mostly to carry all my gear and not so much to actually hike with. I have tried it on and it is very comfortable though fully loaded. There is more room that I thought was in it and I still have room to spare. It current has my d90 with 16-85mm lens w/ hood, nikon 55-200 VR, nikon 18-55, 2 SB-600 flashes, multiple filters, and some more random things. I was happy to find that it fit the 55-200mm lens standing up, which saves tons of space.
Pros: Adjustable Harness, Comfortable, Strong Construction
Summary: This bag is roomier than you might think and has plenty of space for gear (i.e. two D700 SLR bodies with three or four lens, plus other gear). The construction is top-quality and the design is well thought out. My tripod is a full-sized Gitzo and therefore hangs down below the tripod foot pocket, but the three straps the bag has to secure my tripod do a great job of attaching it to the back with no issues.
Pros: Comfortable, Excellent design, Strong Construction