Compressibility
The Down Hugger 800 #1 uses 800 fill goose down which compresses very well. The Down Hugger #1 easily fits into a medium size compression sack and with a little extra work I was even able to squeeze it into a small size compression sack. 

Warmth
The 800-fill goose down in this bag provided good loft and warmth, especially for its weight. While this bag is less tapered than others in this category, the bag still performed well with respect to warmth. The Comfort rating for this bag is 23 degrees F and I found that to be true to performance; in the 25 to 30 degrees F range I felt perfectly warm and slept well. 

Features
Montbell is known for their Super Spiral-Stretch^TM System that uses diagonal baffles and an elasticized thread making the sleeping bag more flexible than other bags. The flexibility allows the bag to move with the user as they move around inside the bag – a great feature for active sleepers.

The hood incorporates a neck baffle that minimizes air circulation. The hood was comfortable until I began to use the draw cord to tighten around the neck and head. As I tightened the draw cord, I could feel the cord in my forehead and around my temples, which I found a bit annoying. The neck baffle did work well and cut down on drafts. 

The Down Hugger #1 comes with dual insulated zipper draft tubes that did a great job preventing drafts around the zipper. The bag also comes with both right and left-side zippers, but the maximum length of this bag is 6 feet, though they do offer a 6’6″ long version.

Overall Comfort
Montbell has a reputation for making comfortable sleeping bags that incorporate stretch. The Down Hugger 800 #1 is no exception. The Down Hugger 800 #1 would have the best stretch in this category, if not for the Klymit KSB 20. The 800 fill down in the Down Hugger is plush and comfortable (other than the hood issue mentioned above). 

Durability
The Down Hugger #1 proved durable and tough even after weeks of backcountry use with no signs of wear and tear including in the zipper and shell. The shell also handled tent condensation well.