Hands down the most comfortable pack I have worn, as well as most functional.
To start off, just looking at the pack, you can tell its durable and robust.
Heavy stitching, thick fabrics, parachute buckle, hefty zippers. This isn't your day to day school pack that you'll take skiing to hold your camera and snacks.
The pack is designed for days out in the backcountry, designed to fit all the gear you need, and (when equipped) designed to save your life.
I could wear this pack all day without fatigue of any sorts. Padded back and shoulders, as well as a removable plastic board that adds rigidity to the pack for maximum support. I find things like strategic support make or break a pack.
The last thing you'd want on a day in the backcountry is a sloppy pack flopping around (mind you, proper strap adjustment also prevents this).
Variety of different carry options such as diagonal, A-Frame (my favourite), and snowboard carry.
The pack also has the perfect amount of storage features. 30 litres is plenty of room for a big day trip, plus the "snowboard carry" doubles as an outer layer holder.
Front compartment holds your probe or shovel handle, as well as a closed off zippered pocket I like to hold spare socks and stuff in. Provides easy access without digging into the bulk of the pack.
Main compartment is deep, and will hold plenty, skins, shovel blade, lunch, layers, etc... As well, it also has the standard goggle compartment, and tool compartment on the the front strap.
What sets this pack aside from other BC packs is its R.A.S system it has built in. This allows a Snowpulse/Mammut airbag (sold separately) to be installed and removed with ease. I haven't purchased the airbag just yet, but it's on my to do list.
Only downside I have found with the pack is the R.A.S zipper function. The pack has a velcro sealed zipper that will burst open when the airbag is deployed. However; when you aren't using it, a full pack or sloppy support management can result in the zipper blowing open on you if it isn't closed properly. To fix this, I've just tied the inside closed with a string, and haven't had any premature zipper blowouts since.
Overall, the pack is the best bang for it's price. The R.A.S. option is great for those who are just getting their backcountry kit together, and would like to invest in an airbag for the future.