New from Big Agnes V Notch UL 40 Sleeping Bag (Primaloft)

Ryan,
I started with down bags, but they were hard to keep dry in long treks plagued by rain. So I swore off them, and went to synthetic; but they often left me shivering at altitude in warmer seasons, even wearing all the extra insulated items in the pack, including puffy jackets and pants from BPL, sox, etc. And those were bags rated to freezing, not just 40 degrees.

So when the first Montbell spriral down baq was so well reviewed on BPL, I got a 20 oz model rated down to freezing and it is still in fine condition. No more shivering during the 3 seasons, it has a very good DWR treatment to repel water, and it’s never gotten soaked or even damp. I make sure I don’t perspire in, under or on the bag (the full zip allows me to keep the feet outside of the bag on warm nights) so I’ve never even had to wash it. I did buy one of the Polish Cumulus Apex bags at around 28 oz just in case a rainy trip seemed imminent, but have never had to use it.

For a long time, I thought about building a super light baffled shell, and filling it with loose 3M Lite Loft instead of down to use as a wet weather or kayaking trip bag, but have never had to go to the trouble. A sealed poly liner in the stuff sack works fine. So, for long distance trekking, even when combined with water trips using a dry bag, I’m not sure synthetic bags or quilts have a place.

If I were going into harsh conditions, I’d consider layering a slightly oversized 2.5oz Apex based quilt over the top of my down quilt.  I would consider putting some snaps into both quilts to keep them attached.  I figure 4 or 5 down each side would do.  I’d try to minimize weight on the over quilt as much as possible by using a 7d fabric for the inner.

Nunatak has basically incorporated this into a singular item called the Nebula.  Layer of apex on top, 900FP down underneath.