This is a great backpack. It served me very well during a recent 3-week trip. It provided plenty of room for additional stuff, which is something that my earlier bag (Lowepro Slingshot) did not. Beside my photo equipment I could also fit in it clothing, powerbars, a water bottle, and other items such as sunscreen and bugspray. This increased carrying capacity when compared to the Slingshot proved invaluable on a couple of occasions.
I took the backpack biking a few times as well, and it proved to be very comfortable. I also took it to the beach a few times, and it protected my valuable lenses from sand very nicely. The tripod carrier is a nice touch!
My only complaint with this bag is that there's not a lot of room for photo equipment in there, and the existing photo compartment is not very configurable. Basically, I could not fit more than 1 DSLR + 2 lenses in there when the shorter lens was attached to the body. The only way to fit 3 lenses was to attach the longer lens to the body and place it in the main section of the photo compartment (accessible from the outside), and place the remaining 2 shorter lenses in the rest of the space. In order to do that, I had to steal and use a spacer/separator from a different bag. Overall a great product. I am giving it 5 stars because it proved invaluable and very handy in spite of its little quirks.
Unconvential photo backpack, Smallish lower section holds pro-dslr with 70-200 f2.8 lens along with flash and/or smaller lens. Upper compartment is high and deep enough to hold my Mark III with 28-70 f2.8 with CB Jr.flash bracket or just clothes and accessories. Access is through back and side panels. Front pocket is large and flat and will hold a small laptop, note book, clothes, etc. Nice tripod holding system. Very comfortable.