About two months ago James DeGraaf loaned my wife and I his Zpacks Twin Quilt to try out. We took it for a 4-day trip in Humphreys Basin and were instantly sold on the concept. First of all, James' version of the quilt weighed 28 ounces - an ounce less than my wife's Western Mountaineering Ultralite just by itself. So it essentially saved us the full weight of my quilt (23oz). I don't think a single piece of gear has saved me so much weight since I switched from a freestanding tent to tarps years ago. It also freed up a huge amount of volume in our packs. My wife ended up using a 28 liter pack that she normally uses for dayhiking on that trip because her gear volume ended up so small.
Humphreys Basin with James D's twin quilt that he was kind enough to loan to my wife and I.
But most importantly, sleeping in it was awesome. I expected to have an elbow in my side for the full duration of the trip, but it actually was quite comfortable and felt roomier than a single sleeping bag. I could stretch my legs out when my wife slept on her side, and we could even sleep back-to-back without running out of room. Pee breaks in the middle of the night avoided the dreaded warming up period when you got back in the bag, because there was a warm body in there keeping things nicely pre-heated. And my wife, who is generally a cold sleeper, was so warm cowboy camping at 30F on a windy night that she didn't have all her layers on thanks to the shared body heat. That's a temperature that historically would have her borderline chilled wearing everything in her WM Ultralite.
Back at home, we sold her WM Ultralite and placed an order with Joe for our own twin quilt. After e-mailing back and forth for awhile, we came up with a revised design for the neck closure which in my opinion is a big improvement over the original arrangement. Basically, each person has a button on the outside corner of the quilt, and there are two button holes in the middle along the top edge separated by about 4". When it's warm out, you attach the button to the outer button hole, and there's a 4" gap between the two of you that gives you extra girth. When it's cold out, you button each corner into the farther button-hole so that the corners overlap by 4" and the gap is closed up to keep out drafts. It's simple, lightweight, easy to get in and out of quickly, and provides some additional flexibility.
Zpacks 20F Twin Quilt, 6' length, 850-fill water resistant down, with a draft collar added. Next to it is my 22F Katabatic Alsek, which has more than 100 nights in it now and is still going strong. Weight for the quilt with DWR down and additional draft collar is 30.5 ounces.
Detail of the two buttons on the neck closure.
As I had heard here on the forums before, Joe was great to work with - he was very responsive to my barrage of questions and worked with me to make sure I got exactly what I wanted.
Since I plan to use this quilt in the shoulder season and in winter, but mainly out of curiosity, I ordered the quilt with water-resistant down. Only time will tell how it holds up with age and how it performs in bad weather, but as delivered the quilt is very lofty. It seems identical in loft to James D's 900-fill quilt and has very similar loft to my 22-degree Katabatic Alsek, pictured next to it.
A $600, two person quilt is a bit of a niche item, and I can't imagine too many people on this board needing one. But if you backpack often with a significant other, it can be a great way to save a significant amount of weight. I'll update this thread as I get some more use out of the quilt.