I liked the Hydrogen but because I spend more time at higher altitudes, I ended up with a Marmot Helium. It is 1 lb 13 oz. and rated 15 degrees. I've had it down around 20 without being too cold. To me, the most amazing thing is that someone who is 6 ft. 225 lbs (me) finds the regular size bag roomy enough. Not true of a beautiful old Sierra Designs Cloud Series bag I bought in the 70s when I was well under 200 lbs. [Used it extensively and it is still in good shape for girlfriends, after laundering by a specialist.] A couple of the lightest Western Mountaineering bags were also too tight on me---although very nicely made.
As noted above, the downside (no pun intended) of a bag like the Helium is that it will not be comfy at 60 degrees unless you open it like a quilt and drape it over yourself.
DancesWithKnives
As noted above, the downside (no pun intended) of a bag like the Helium is that it will not be comfy at 60 degrees unless you open it like a quilt and drape it over yourself.
DancesWithKnives