Originally Posted by Cannibal
Well first of all, I didn't vent on purpose.
It probably just slipped off during the night. That particular UQ was very much a prototype and there were some weaknesses compared with the final production model. Most notably being that it didn't 'cup' the shoulder the way the down Yetis do; hence the slippage.
I'd have to weigh it, or find the old thread. Honestly, I think that thread is one of the ones I deleted when I had a fit of anger at some point shortly after I got home from the AT (it's a bugger of a transition back to the "real world"). However, I really want to say that quilt was right at a pound (16oz). I'll throw it on the scale tonight to be sure.
I realize this is an AHE thread too and tried to focus more on the material than the construction. I do think the XP was very close to down in terms of insulation. At the same time, I have a theory on why the top quilts made from the same material aren't getting the same results. As we all know, CBS generally comes from gaps between the hammock and the quilt. The Yetis, as well as the KAQ I have, both seal-up extremely nice to the hammock. I can only assume Paul's continuation of the KAQs function and fit nearly, or better than the originals cause Paul's work does not suck! But a top quilt? They don't really seal, they just drape and synthetics don't drape half as well as down quilts IMO. *I think*, that synthetic insulation works great when it's against, or very nearly, your skin. It traps the heat quickly in that situation. When draped and pockets of air form, I believe it isn't nearly as efficient. Made more exaggerated by a sleeper that tends to roll around....like a groundling.
While I am still a semi-fan of synthetic insulation in underquilts, I am pretty exclusively a down-guy for my top quilts. I have a couple of synthetic top quilts, but they are strictly loaners. I don't think a synthetic top quilt, gram for gram, can take on a down top quilt.
And yes, for a top quilt in that picture I was using a very old synthetic bag. If memory serves, it was a Coleman bag. It was either a 0° or 15° bag. Plus a base shirt, plus a cotton shirt, plus a fleece pullover, plus a hoodie, plus...you get the idea.
I think you are on to something about CS TQ function vs UQ, particularly for groundlings. That was the conditions I was reading about last night, with results not nearly as good as we have had with that CS UQ. These were groundlings using CS TQs, and they were having to use much higher weights for warmth at 30. They were side sleeping and most likely changing position frequently, the way folks on the ground tend to do. They probably were not getting near as good of a "drape" as they did with nice down TQs.
More info on the comparison of CS to down in an UQ, per Paul's IMO conservative ratings:
Flame thrower 40X54 UQ with 9 oz of 800 down, total wt 16 oz:
This quilt is taking most users easily to 30 degrees and some even lower. So far we have heard of one user hitting 19 and they said they were toasty.
Jarbridge 42X58 ( a tad bigger than FT ) with 1 layer of 6 oz/sq.yd standard CS XP ( ? ) total wt 20 oz:
3 Season Rated to the 30's for most users
But several folks here have gone lower and I think 1 person said they were warm at 9F?
So, basically the same rating from Paul, the JB is a tad bigger than the FT and weighs 4 oz more. Again, to me, that is not a huge dif.
So OP Nathan, I don't think - at least for UQs - that warmth to weight is a big enough reason to choose down, especially if giving any consideration to performance when damp. Or if sleeping out in a snow storm with no tarp!
And of course there is a pretty good initial cost advantage to the Jarbridge.
Much smaller pack volume would be a good reason to choose the down for those with smaller packs. And maybe greater longevity.
Edit and PS: Cannibal, I have not been able to verify any difference elsewhere, but I guess Paul knows, and he offers that Apex upgrade that he says is 5-10 warmer than the normal XP in your quilt. If that proves to be the case, then the difference between down and CS shrinks even more.