I have seen and tried these bags, they are well made as far as camera bags go.
However, my advice for hiking is always the same. Do not get a "camera bag". Get a true hiking bag, well fitted for your body shape. Then add an insert. You can get a bag with a top and bottom pocket and fit an insert at the bottom. You'll end up with a much better fit, more confort and convenience.
For instance (not saying you should get that one) I got a McKinley Lynx 28:
It has a mesh back (something most camera bags lack), strong support, a hook to attach a monopod, side pockets that can hold a light tripod, room for a water bladder, a rain cover in a hidden lower pocket, a bottom compartment where I perfectly fitted an Ape Case (15$ on Amazon). I can put in the K-3 with Sigma 17-70 mounted, 2-3 primes and a flash or accessories. Only large lenses like the 60-250 can't fit, but when I really need to carry it I put it in its dedicated bag, in the top compartment.
I'd get something like that if I were you