Great pack! Very comfortable!
I have the 2011 model of this pack, but I've seen the 2012's at the store and tried them out. They are pretty much the same as the 2011 with a few minor changes (i.e, the location of the bottom compression strap). he kestrel is a great series. I really like the way they fit and distribute the weight of the load. I dry camped with mine, so I was carrying 14 pounds of water alone and it held the extra weight great. My total pack weight was 45 pounds including water and food, and I had no issues at all.
There are plenty of compartments for very easy access to your gear with tons of space inside the main section as well. The side pockets stuff to the inside, so they are a bit of a pain to pack once the main compartment is full, but not too bad. I really like the hydration sleeve being on the outside. You really don't notice that the bladder is even there (I use the Osprey Hydraform). It is a bit of a pain to pull in and out with a full pack though.
Lot's of places to clip on gear if you need to, including a very convenient place for your trekking poles. This pack really has everything I would need in a backpack. And you have got to love the integrated rain cover! All in all this is a great pack that will do well on an extended trip.