I saw your review on bags but it never went into any detail on the material Gore Dry Loft. I see that a few companies are using it.
I'm concerned with the frost that tends to build up on the exterior of the bag and inside the tent in cold weather.
I'm wondering if Gore Dry Loft is a better material than others available to protect the down insulation from getting wet.
I currently have a Marmot down bag with a nylon exterior. I haven't had any problems yet but I'm frightened over the thought of getting screwed sometime.
I'm sold on the down as insulation and don't want anything else. Besides, it really packs down in size as compared to man-made materials.
I thought I would try to share what I know about Gore DryLoft. I'm with you, I love my down bag. In fact, I own a Marmot and have spent many comfortable nights in it.
When I bought the bag, I chose to have the Gore-tex option, thinking that it might come in handy on a wet night. It has.
Now, the industry has come to the conclusion that Gore-tex keeps the water out terrifically, however, it also traps in moisture from a sleeping body.
This moisture in the down lowers the insulating qualities. So, Gore has come out with something new, DryLoft.
It is a waterproof, windproof fabric laminate that repels water, although not as well as Gore-tex, and allows much more moisture out.
The theory is that your insulation will stay more dry, keeping you warmer.
As to whether it is better than other materials for keeping you dry. I would have to say it is better, for the most part.
You are right about being concerned about water because wet down is no good.
DryLoft is deffinately better than a non-treated material. How it compares to other treatments,on the other hand, I can't say.
I do know that the Feathered Friends bag I reviewed had a DryLoft shell. We never had any problems with the morning frost buildup and the occasional drips of water from the tent.
I thought it worked well, just as Gore claims.
I have included a link to Gore's site where you can read more about the specifics of DryLoft.