Big Agnes Zirkel $399.95
Rating 20 F
Field Rating 25 F
The Big Agnes Zirkel has no down on the bottom. Since the down you lay on gets crushed, and you need an insulating pad anyway, why even have an ineffective bottom layer? So, instead of placing down underneath, Big Agnes uses an integrated (and removable) Primaloft Dual Core Air Pad ($99.95; 1 pound 15 ounces). In theory this is like sleeping on a pad with a down comforter zipped over you. However, for this to work comfortably you need room to roll over in the bag, as the bottom cannot move with you. If you are a big fellow, you might find the mummy-cut Zirkel too snug, forcing you to sleep on your back.
A Pillow pocket in the hood works well with a down vest or clothing.
Plump draft tube behind the zipper.
Don't need to mortgage your home.
If you're skinny enough or sleep mostly on your back, this is a comfortable bag.
The Primaloft pad can be blown up by mouth, unlike down-insulated pads that require a special bellows.
Zipper isn’t two-way.
Not a good bag for extending the temperature range—it is too tight to wear a down jacket and pants comfortably inside.