"This is a "Purpose Driven Backpack", but one which is a stellar choice for many activities.
I used the pack while skiing the Lake Tahoe area with my son. Skiing in a place with radical weather changes requires the ability to change layers, frequently, and skiing with a 12 year old more than doubles the amount of stuff you need to bring and use. Clothing, food, hydration,... as well as some extra equipment like googles and glove liners, glasses, etc... I particularly liked the many storage areas and compartments for segregating items I would need repeatedly or rapidly. And the compression straps allowed me to wear the pack close to my body, never interfering with skiing or getting on and off the lifts.
I also use a pack to travel at all times, and this pack easily carries a laptop, books, mags, and other items while fitting nicely under the plane seat or in the overhead compartment.
I have been impressed with the technical planning and construction of this pack. It is well designed, and performed exceedingly well. It is a comfortable pack, bearing the load (up to 25 lbs) without difficulty or discomfort. It is also very easy to access the bag from several points.
The material on the upper portions of the bag are silicon impregnated, and proved VERY waterproof, having had snow falling on it for extended periods without penetrating the pack, as well as having snow and melting snow mashed into it without problems (yeah I wiped out a few times).
The only concern I had while using this backpack is that the lower portions of the suspension has several straps which I got tangled in while removing the pack if I had had it tightly pulled/secured to my body.
I would highly recommend this pack to anyone interested in a very lightweight and effective piece of equipment. I look forward to using it for other activities as well."