The Loka is meant for day trips, first and foremost, even if you can easily fasten a tent and all kinds of stuff on it, however even with only a medium pro ICU, not a lot of extra space is left in your backpack and especially not enough to take a stove and food for several days of hiking.
If that is what you need, then one should look at the F-stop Satori EXP instead, which I myself will get for next year's hikes and adventures.
Like I said earlier, this backpack is better than anything else I've owned/seen/tried and I could declare that F-stop simply makes THE best camera backpacks available today.
But of course, things could still be improved, and for example the carrying handle that you use to lift the pack with one hand is a bit too thin and could be bigger/thicker.
It doesn't come with a rain cover, though it's probably not very often that you need it, but still. F-stop backpacks are quite expensive, but then again, quality is usually not cheap. And also, it can be quite hard to even get your hands on one. The people at the customer service are friendly, but otherwise the actual service (as in delivering orders to people) needs to be improved.
But as a conclusion, these backpacks (including the Loka) are as good as it gets. If you're a serious shooter, do yourself a favor and get one.
F-stop website
Edit:
I forgot this, so I'll add it here. Thanks to a (very very stupid) corporate decision, F-stop stopped manufacturing the Medium Pro ICU a while ago (I was lucky to get my hands on one), which I see as the ultimate ICU since there's room for quite a lot of gear (I usually have my Canon 5D MkIII w/ battery grip, Canon EF 17-40mm f/4 L, Sigma AF 50mm f/1.4 ART, Tamron SP 24-70mm f/2.8 VC, remote, CF-cards) and still it leaves some space in the Loka for additional gear (since my Lee filters take up a lot of space, I keep them inside of the backpack but outside of the ICU in a Lowepro S&F filter pouch). I forwarded my complains about it to customer support and they told me that other people have done the same, so hopefully they will bring it back.