Comfort/Fit
With the Bora AR 50, Arc’teryx employs shoulder straps that are adjustable along two dimensions, which is easy by pulling the Velcro back and adjusting the strap to choose a new set of coordinates. This technology allows easy in-the-field adjustments. And once it’s set to a back, it remains a customized backpack. The padding on the waist belt is extraordinary, and this pack is the most comfortable in the set, by a healthy margin, full stop. 

Storage
The Bora has simple and efficient storage. On the back there is a full-length sleeve for accessible items, which is fastened by a button on the top and a waterproof zipper along the back. The body compartment has a small zippered pouch and a water bladder sleeve. The brain has one large-ish pocket on top and a small zippered pouch on the bottom 

Stability
The Arc’teryx Bora AR 50 earns high marks in stability. The flat carbon fiber frame provides a rigid structure upon which is mounted the waist belt, which pivots nicely on its circular mount. This provides unmatched comfort and stability when it’s loaded down with loads up to 40 pounds, because your back is able to stretch and move in a natural way, unlike pivotless packs. There are two linear straps on each side, which allows the user to lock down loads to prevent shifting or imbalance. 

Durability
This pack has unmatched durability. The durable water resistance treatment provides reliable water resistance. This beefiness does add to the weight, which is this pack’s only real non-price drawback. 

Extras
The Arc’teryx Bora AR 50 has few extras, which highlights its simplicity. It does have two gear loops that can be used for trekking poles, ice tools, or other technical gear. The toggle that fastens the gear is adjustable. Both hip pockets have tight elastic mesh pouches.