Storage
The Mystery Ranch Sphinx has some of the best storage options I have tested in a backpack. The lid contained a large wraparound zipper that enabled great access and lots of storage. The two vertical Terra Plane pockets on the outside of the pack were born years ago in the original Dana Design series of packs are large and great for storing extra clothes, rain gear and many other articles that you want to have quick access to on the trail.  

The main storage area of the Sphinx is one large main compartment that swallows large amounts of gear, clothing and equipment. This main compartment has top storm flap access, bottom sleeping bag compartment access and a large zipper that bisects the pack in half. This large middle zipper essentially filets the pack open allowing you the ability to open up and see the entire contents of the main compartment. I loved this feature and so did everyone that backpacked with me during the testing phase of this pack.  

The two zippered pockets on the hip belt are perhaps the largest that I have seen on any backpack. On the down side, the two side stretch water bottle pockets barely hold a 1 liter water bottle. They need to be a bit deeper to really secure a bottle. When scrambling on steep or rough terrain, I had a bottle fall out of the pocket a couple times. The Sphinx 65 utilizes the normal internal hydration sleeve to store up to a 3 liter hydration bladder.  

Comfort
Hip Belt 
The Sphinx hip belt has a thick and comfortable padding that has a wraparound effect making the belt fit comfortably. The hip belt has two zippered pockets that may be the largest I have tested in any pack. I was able to store a small camera, an iPhone, a beanie, several bars a Buff and a GPS in the hip belt pockets.

Back Panel/Shoulder Straps
The Sphinx has a supportive and adjustable back panel. This added to the packs overall comfort and while the back panel provided adequate ventilation, it was not quite as good as some of the other packs in this category. The shoulder straps were comfortable and had good padding adding to the packs overall comfort.  

Stability
The Sphinx was stable and comfortable carrying loads in the 40 to 50 pound range. The Sphinx did not move around or float despite scrambling up steep ascents and descending rugged mountainous terrain.   

Overall Comfort
The Sphinx provides very good overall comfort while carrying loads up to 55 pounds in a variety of conditions. The pack’s good padding and easy adjustments contribute to it competing well in this class of packs in terms of comfort.   

Durability
The Sphinx proved durable in a variety of conditions. The zippers, pockets and fabrics all performed well and despite weeks of rugged use. The Sphinx showed little wear even when dragging the pack through a slot canyon over rocks and debris.