I have not seen a Hexamid, but did get a chance last year to give
a Zpacks 20f bag a look over, its very indeed and seemed as lofty as
my WM Alpinelite. I recall the stitching and build is on a par with my Enlightend Equipment quilt, and very close to WM.
I am back in July if you wanted to get them sent to my placee, and I could post from Ireland.