Marmot Helium EQ Sleeping Bag

Thru-Hike Worthy
This bag performs great within the realm of its features. I used the Helium during the chilly early months and again in Maine during cooler nights at higher altitudes during my AT thru-hike. The bag was warm at 4,000+ feet with temperatures around 20 degrees. I never needed to wear extra clothing for warmth. The bag has great loft and is durable. I highly recommend this bag.

Great bag, glad I got an earlier model with the full zipper
I love my Helium EQ! As a cold sleeper it keeps me warm to about 35F in nothing but boxers, about normal for me in a 15F bag. But the light weight for the rating and water resistant shell are great for camping in conditions that result in condensation on the tent walls (or drips from the ceiling of a snow cave) where the bag gets moisture on the outside, yet the down stays dry. I bought my bag 3 years ago back when it came with a full length zip. Not sure it's worth saving an ounce to loose the flexibility a full length zip brings - it's not worth it to me, but if you're ok with hot feet on warmer nights, don't let the 1/2 zip stop you, everything else about the bag is great. The only thing I wish it had was a draft tube collar as that would extend the comfort range another 5 to 10 degrees cooler.