Compressibility
The Fish Hawk 30 packs into the included 8”x6” nylon stuff sack with an average amount of effort. By using a third-party compression sack, it could be made smaller to the size of a large watermelon. Even with the compression sack it is—by a fairly significant margin—the largest of the five bags within this category.

Warmth
The Fish Hawk 30 uses Big Agnes’ Sleeping Bag System, which relies on insulation from the sleeping pad rather than providing down on the bottom of the bag. I do not typically find insulation from a sleeping pad adequate for good warmth and, like most other bags in this category, the Fish Hawk 30 did not perform well in the lower ranges of its temperature rating. The DownTek^TM treated down repels moisture, improves loft and dries faster – all factors that help improve heat efficiency, and the bag did perform much better in temperatures approaching the mid 40s. Also, because the bag is a little more roomy than others in this category, it is easier to create some draft in milder climate. 

Overall Comfort
Because the Fish Hawk 30 is intended to fit more like a comforter than a conventional sleeping bag, one would expect it to be roomy and cozy – and it lives up to that expectation. Since a user can’t fully use the extra space due to the narrower sleeping pad sleeve beneath it, its overall comfort is negatively affected.

The Fish Hawk does also use a very soft, breathable down proof polyester (to prevent the down from poking out) which feels smooth and silky.

Durability
The Fish Hawk 30 showed no signs of wear and tear during the testing phase and I have no reason to expect it would do so with continued use. Big Agnes uses a down proof, nylon rip-stop shell along with a down proof, polyester, stain-resistant lining, both surfaces are treated to help repel water.

Features
The Fish Hawk 30 features a semi-rectangular shape unique to Big Agnes’ Classic line of sleeping bags. The Fish Hawk 30’s trademarked insulation system keeps the DownTek^TM treated down evenly located around the body and it is very cozy that way.

The vaulted foot box is a particularly attractive feature for back sleepers and contributes to overall comfort. The one-hand hood synch cordlock in the hood area is a really nice touch that I found easy to use.

The Fish Hawk 30 has a robust draft tube along the full length of the zipper with an extra wide seam along the zipper, making the snag-free zipper truly snag-free. It also features Big Agnes’ half-moon shaped draft collar – which as I’ve reported in other reviews for Big Agnes bags with the same feature – is cumbersome for active sleepers; it’s a unique feature specifically designed to minimize draft but for those who move around a lot during sleep, it tends to get in the way.

As part of Big Agnes’ Classic Series, the Fish Hawk 30 is designed as part of a Sleeping Bag System. It features a stretch fabric panel on the back of the bag to slide your sleeping pad into. While I generally appreciate the roominess in the sleeping bag (especially in more mild temperature when a close-fitting bag can easily become too warm), the sleep system introduces a problem. Because the Big Agnes Double Z Airpad (an intended part of the BA sleep system) is narrower than the bag itself, the user loses the benefit of the extra sleeping bag space. For example, if I wanted to stretch my legs or arms to take advantage of that extra space, those extremities end up hanging off the sleeping pad and onto the ground.

Nonetheless, for those who appreciate a sleep system, Big Agnes is one of a few manufacturers that offer it (along with Therm-a-Rest and Sea to Summit, also featured in this category).

The YKK #8 zipper can be mated with that of another bag should you choose to cozy up with someone.

A final note goes to price:  The Big Agnes has the best price point in the category.