Compressibility
The 650 fill down and larger width compresses down to the size of a small soccer ball. While this is small, compared to the other bags in this category, the Fish Hawk and the Blue Kazoo were the least compressible.  

Warmth
The Big Agnes Fish Hawk uses the Big Agnes’ Sleeping Bag System and thus there is no down fill on the bottom of the bag, instead relying on the sleeping pad insulation to help keep the user warm. I generally like having down in the bottom of the bag, but wasn’t bothered by its absence here; I found the Fish Hawk to be comfortable in temperatures down to the mid to lower 40’s. However, in temperatures lower this this, I had to add layers of clothing to be able to sleep comfortably. The DownTek^TM treated down helped to improve the loft and the warmth of the bag. Due to the wide design of the bag, the bag was also comfortable in warmer temperatures and it was easy to move air with the zipper and width of the bag. 

Features
The Fish Hawk features the traditional Big Agnes semi-rectangular shape, which provides more space for those that move around or have a larger frame. The vaulted foot box allowed me to comfortably sleep on my back and provided plenty of room for my large feet no matter which position I chose. 

The one-hand hood synch cord lock in the hood worked well and is easy to use, but the hood is small and when cinched tight I could feel the draw cord on my forehead. A robust draft tube along the full length of the zipper worked well at keeping draft at bay and the stiff zipper tape provided a snag free zipper every time, making it the best zipper of the bags tested in this category. 

The Fish Hawk 30 uses the Big Agnes Sleeping Bag System, which incorporates a stretch fabric panel on the back of the bag which houses a Big Agnes sleeping pad. Unfortunately, to really take advantage of the width and roominess of the Fish Hawk, a sleeping pad wider than 20 inches is required, since the bag is much wider. I found the 20-inch pad to be a snug fit and found a 25-inch pad very difficult to use with this bag. 

Overall Comfort
The Fish Hawk is designed for that comforter feel and hits the target in this area. The bag is wide and allows the user to stretch their legs out and move around easily. The downside to this extra space is that if you use the Big Agnes Sleep System (sliding a pad into the built in sleeve on the back of the bag) I found it difficult to use a sleeping pad wider than 20 inches as stated above. The Fish Hawk also uses a silky feeling, breathable polyester on the inside of the bag, which feels very nice. 

Durability
The Fish Hawk 30 has a tough and durable shell that showed no signs of wear and tear during the testing phase. The Fish Hawk also has great zipper tape, giving it a snag free zipper and the best zipper of the bags in this category.