User Review: The North Face Dark Star -40
Fill: Polarguard (2000 model year)
Temperature Rating: -40 (F)
Weight: about 5 lbs
Price Paid: about $300
I bought this to replace another North face synthetic bag that went flat. Nothing against The North Face, they are a good company, but I find all synthetic bags to be lacking in durability and warmth. I used the -40 (F) Darkstar in temperatures that were around plus 15 (F). I would have died if the temp was -10 (F) in this bag. It is just not that warm. I don't know how they test these bags, but the ratings are all wrong.
I opted to go for a down bag. TNF was gracious about it and allowed me to upgrade for a modest cost to a -40 (F) down bag from their line.
I have a 25 year old down bag from REI that still lofts up like it was brand new. I never got more than 3 to 5 uses from a synthetic bag before it would loose about half the loft and insulation rating.
I don't like to be cold at night after a long day hiking in the snow and ice. If it is really cold and dry, I like the down option better. (my opinion)