I am interested in a lightweight version to 20 degrees....anyone have any experience with this new down treatment. I am interested in one that is well under two pounds.

I watched this technology like a hawk. According to Outdoorgearlab and several reviewers on REI and elsewhere, the down treatment makes a considerable difference over regular down. It retains more loft when completely soaked, and it dries faster.

However, when it is completely wet, Synthetic is still warmer. it isn't as warm as synthetic in a downpour.

Where does that leave you? Depends on your needs. For me personally, I carry the extra 6-10 ounces of a synthetic bag happily, since dying of hypothermia in a situation where I can't get my bag dry doesn't appeal to me. Do I carry it in a waterproof container and only take it out in a shelter? Sure, but unforseen circumstances happen. Rockslides, hurricanes, bear attacks, tent-eating bacteria... who knows! I'm ready.

I was recently searching for the same thing. Unfortunately...... I don't think that such a bag yet exists that exactly matches your criteria made by major manufacturers. The closest thing are the ZPacks "sleeping bags", which are offered in 850 fill dri-down.....but these are really quilts and not sleeping bags. At present, most of the dri-down bags are 600-700 fill, which makes them heavier (like Sierra Designs).


For an actual sleeping bag, the closest match that I've found is the Sea To Summit Talus TsI Sleeping Bag: 23 Degree Down . It's 1 pound 15 oz. and it uses 750 fill down.
http://www.backcountry.com/sea-to-summit-tsi-sleeping-bag-23-degree-down
I am weighing this option against trying a quilt. Since I'm tall, I'd have to go with the long 2 pound 3 oz. version. The 2D Nanoshell technology and its roomy mummy fit sound very interesting, but its so new that I can't find much reviews on it yet, nor can I see it in any local stores.

There's a video on it here:
http://www.youtube.com/watch?v=vqzolgQ7voQ&feature=player_embedded
but its put out by sea to summit and they've disabled comments (:

I would expect to soon see 800+ fill lighter options.

not sure how well it works, but they have some lightweight sleeping bags with dwr down inside.

http://www.mec.ca/AST/ShopMEC/SleepingBags/DownMummyBags/PRD~5025-629/mec-merlin-df-sleeping-bag-10c.jsp

My opinion is that DriDown is for most part not needed in a sleeping bag. There's no real harm in having it, but I wouldn't buy a sleeping bag just for that, nor accept a significant weight penalty. A better application for DriDown is jackets, where a down jacket is pretty likely to face moisture/water in extended wet conditions. DriDown could extend the use of down jacket into synthetic jacket territory, but for true sloppy cold conditions fleece is still king.

I've camped in sloppy conditions all over the PNW and I've never had a problem keeping a down bag dry. If it's going to get wet, it would likely happen when it's in my backpack but I keep mine in a cuben drybag and I think with a reasonable amount of prudence the risk is negligible.

I also don't think of synthetic bags as saviors when things get soaked. Synthetic may be less cold than down in an exposed downpour, but they still get really cold when wet, which is still a miserable and potentially dangerous situation. Ultimately the key to staying safe is to take care of your stuff and avoid these situations instead of packing extra gear to make mistakes suck less. For the added weight and bulk, synthetic bags don't provide much of a practical safety margin if you get your bag soaked. I'd rather just keep hiking all night than crawl into any drenched bag.

The best application for synthetic bag and DriDown bags is long trips in extreme humidity like 9 days in the Amazon. You can't avoid getting extreme humidity in your bag if it's 24/7, so in this case synthetic and DriDown would be superior over regular down which would lose loft faster if it's not dried somehow.

Edited by dandydan on 01/20/2013 20:40:18 MST.

There is dry down and there is DriDown...
DriDown is the brand name for American Rec's (Sierra Design,Slumberjack,Kelty ...) version of their water resistant down.
The type used by some cottage manufacturers is from Allied Feathers and called Resist Down.
Down Decor has DownTek and Patagonia has Encapsil.
Sounds like BPL will have a report on the difference at some point but for now let's not talk about it as if there is just one version or were all the same.

Have these bags been tested in high humidity. I haven't paid that much attention but the test I have seen all involve soaking the bag with water and drying it out. In hundreds of nights the worst I ever did was get a slightly wet footbox. So I don't need protection from soaking. Are the Bags resistant to vapour reducing loft. My understanding is that most DWR causes droplets to role off and prevent stuff from getting wet. This seems different than how humidity makes stuff damp. Anyone have any info.

I bought the 30 degree Sierra Design Dri Down bag a little while ago quite discounted, and about 3 weeks ago, when hiking in the Shenandoah/Blue Ridge VA area tested it out. The weather forecast called for a clear night for that area, and since we weren't that high up or that far into the "mountains" yet, i thought it would hold true for where we were.

I had also brought my homemade tyvek tube tent, which is really only a 1 p size. I was going to cowboy camp for the night and let my wife sleep in the tent--for whatever reason, i decided against it when it was still clear. It was unusually warm and humid that night, and then the fog and rain rolled it. I hadn't found a fully level ground to pitch the tent on and so we would slide down the tent a bit on our sleeping mattresses (i need to do some silicone dots or something).

It was sucky, wet conditions, and i was surprised at how well the bags did despite the very, very high level of humidity, the condensation that was dripping off onto the bags, and occasionally sliding the bags out into the rain a bit (thankfully the rain was light). It kept very lofty (well, as lofty as 600 fill is going to be, wish they had a better quality option). This was only a weekend trip, and when we got back, i threw the bags into the drier and they seemed completely dry after about 20 or so mins. on low/medium heat (they had probably dried out in the car some too, since it was quite warm and sunny the next day).

My question is, how long will this last though? If i hadn't gotten the bags quite a bit cheaper than their regular prices, i probably wouldn't have bought them. I sold my new Golite Adrenaline 40F + bag recently--certainly miss the compactness and low weight.