The Zpacks, from the photos, is sort of a hybrid, as the zipper is along the back.
That said, compressed down does not insulate to any significant degree (at that point it's just like having a thicker material down there). I like the idea of a hybrid sub-zero quilt that has just material down there to act more as a wind wall than for any insulative properties. Is the extra weight worth it for that? dunno, but interesting in concept... That said, if you're wearing clothes and down jacket/pants and such, I don't know if you'd feel a draft at that point?
The Enlightened quilt should be plenty wide enough to cover your body+clothes.
remember last winter, Lupus and I both fit under my GoLite quilt.
Has anyone proven that over stuffing without the added volume for extra loft will actually add to the insulation level?
As I understand it, down has a optimum fill volume, following a bell curve of sorts, anything below or above that optimum does not increase the insulation value.
Like many things I see manufacturers do, this is one I have yet to see any hard evidence as to the engineered benefits. This is a call out for someone to enlighten me on the subject!
Grain of salt and all that, as those that know me, I'm as nitpicky of an engineer as they come.
I like the idea of "water resistant" down, but at those temperatures (below freezing), if you get your down wet, you have to hope it's sunny enough to be able to hang it and hope it does not freeze, AND it dries, AND you have to wait for it to do so before packing it away to move on, so as to be able to use it again the next night. So in the end how useful is it really? Does it make sense to try and rely on it?
Just my thoughts on DWR850 vs their standard 900fp.