My Tenba PBP (Photo BackPack) is among the best photographic equipment I own.
That is same statement as a poster replied on my question on Nikonians in end of 2002 about Tenba as alternative to the big brands such as Lowepro and Tamrac.
Sadly Tenba do not make the PBP or anyhing similar to the PBP anymore. Luckily I found a new one hanging collecting dust in a store in Shanghai earlier this year. It is now my backup for when my first PBP will fail (although I estimate that will be a many years from now still). I use it with a Kinesis padded belt. Straps at sides hold my Gitzo.
Why is it so good?
Comfort. When trying it out in Nov/Dec 2002 comparing to Lowpro Nature Trekker, the PBP felt like half the weight on my back (using camera gear for test loading).
It has a quick access draw opening. Soft to form shape against back (not hard box). Protects gear perfect. No special notebook sleeve, do not know why needed. Have neoprene sleeve for my notebook and sticks it inside lid on PBP. Perfect.
I always carry my PBP on flights with my Gitzo at side, never rejected to do so (although at very limited numbers of check-ins I had to speak myself to it...). So far it has been with me on my many numerous travels all across Asia, to Europe and back, and my grand voyage round the world in 2003. Without it I simply could not have carried at times up to near 20 kg gear on my back (usually though it weighs 12-16kg loaded). When I was younger I had back problems. Non so with the PBP. Hiking boots are essential for stability and not wearing of ankles. I use Garmont. Same as my PBP, light weight, tough, comfortable.
As expat living in different places and being on many travels each year, my PBP is truly essential to my photographic hobby. It is difficult to find light weight, comfortable, tough & reliable carrying gear. Has it seen tought life? Yes. Budget camping in Africa, up to the peak above Machu Piccu, horseback up mountain with budget camping in Sichuan China, jungle, desert, hot, cold, clean, dirty... name it, all.
Attached photos are from several years back. I now have upgraded just about all my gear, but my PBP is still same .
Tenba, are you listening???
To add, per my experience there are many bag fabricators and photo back packs of all designs, but very few appear to be designed by people who frequent travel and carry much gear. Gear weights, the bag shall be light weight, yet tough. Convenient for pulling gear out quick and for reaching all gear simply from main compartment. It shall be comfortable to carry. It shall be theft safe with easy lock of a main and secondary compartment when leaving it at hotels. There is not more comfortable way of carrying camera gear than in a backpack but it need comfortable supported on shoulders and hip and with soft towards back to adjust to contour of back (not hard box).
When carrying only camera and one or two lenses I use soft wraps in small regular non camera back pack (=light weight). Drinks etc for hike go in my PBP secondary compartment, well away from camera gear. Alternatively clothes can go there for one day change. For longer travels like my trip round the world I had a light weight duffel bag for clothes. Travel with two light weight sweaters and T-shirts keeps down on weight of clothes.
My advise for anyone buying is to look at many and think carefully for your use. Test load them with your main gear and feel the weight of pack alone without gear in it (if you buy heavy bag, then can carry less gear ). Your need may differ from mine, but above is per my experience of many global travels of all kinds with my gear