I got the naneu pro Alpha (the non L version) last week and returned it. The camera compartment was tiny. Somewhere along the line Naneu redesigned the alpha backpack and the newer version has a smaller camera compartment than the one I saw on some images posted around the net that showed the camera in the center of the compartment and lenses on either side. The only way I could get my 1ds 3 or my 5d in there is to put a divider close to the middle so the camera is just bellow center and with only one or 2 smaller lenses on the side/front of the camera. (infront of the shutter button). The build quality of the bag is quite good and it held my tripod comfortable and securely (series 2 gitzo). The straps and waist belt were nicely padded and comfortable. BUT, yeah, there is always a but. The bag was way to short for me. I had to loosen the backstraps almost completely and move the sternum straps all the way down and they still were a tad high. I am 6-2 (but slim, 185 lbs), this bag is for someone up to like 5-10. I mean it was quite usable for me and not too uncomfortable but certainly not for 2-4 hour hikes on mountaineous terrain. The top compartment is also quite small but usable.
I am considering the Tamrac Adventure 10 . It still fairly light (5-6 lbs max) and seems long enough for me and large enough for camera and other gear but not excesively wide like other photo backpacks. I will have to modify it by adding a strap or to to carry the tripod on the side and other dirty gear (a wet jacket, socks, sandals whatever) that must be carried outside the bag (there is a local rock climbing store that has tons of accesories) no worries since the bag is well under $200. I dont need the laptop compartment but its a nice feature for travel. Inside the bag i will carry extra clothes, food, dry sandals and maybe a dry towel + other misc. gear.
Its tough finding a right bag.
I took a long look at the Gura Gear Kiboko bag. Looks awesome. Seems that I can use one side for clothes etc and the other for the camera gear. having dual compartments have a ton of benefits (when working out of the bag etc). I am surprised that not many other bags have that design (either vertically or horizontaly split) Its light which is quite nice. Seems comfortable enough. Dunno how it would do in the rain?? But should be good enough to hold up according to the spec materials although its quite expensive. I dont have any super tele lenses (longest is 300mm f4) and the bag is definately designed with those in mind but i guess I can subdivide the space as needed.
The Lowepros are nice. But seem heavy and unless I get into something like a photo trekker or larger, too short for me I think. Maybe a nature trekker its the smallest I can go with. But i dont intend to go into the woods with a ton of camera gear. 3 lenses, maybe 4 tops and none larger than my 70-200 2.8 IS.
I also looked at the Kinesis Journeyman. Seems like a very nice solution but one needs to buy a lot bits and pieces o make it work (which is good and bad), can get expensive.
A lot of bags are made with Airline travel in mind like the Kiboko (seems to be the best one of that kind, seems long enough and comfy) and so are boxy, short and without many pockets, straps, loops outside that you can strap or hang stuff from. I usually take 2 bags when I travel, one to go through the airports with all my gear on me and another to shoot on location. Sometimes I might take 3, the other ones i check them inside my duffle. I dont expect a bag to do everything well. Its ok.