Javan - I hear you about the zipper, but it if winds up being a problem in practice I'll likely sew in some zipper backing I have on hand from thru-hiker. I thought about omnitape, but went with the zipper as I had success using it in my other topbag.
Aaron - I may have beat you to the punch, but I am still very interested in seeing what you come up with...the more MYOG examples we have on here, the better as far as I'm concerned. Also, in spite of the fact that this only has 9 oz of down, I think it will be quite warm: the top bag design really concentrates that down where it matters and makes it a very efficient 9 oz. I've got a whitney down parka with 6.4 oz of down for 13.25 ounces total, and pairing this with the whitney ought to make for a system that can be pushed below freezing if necessary.
Christopher and Jared - The foot box consists of a rectangle with one horizontal baffle, which is sewn into the quilt aound the perimetier (not baffled). This is one spot in the quilt with sewn through construction, but I don't think it matters much because it meets up with the rest of the quilt at a right angle, and doesn't leave a cold spot. I'll try to put a photo up in a bit. I used the thru-hiker quilt kit, which basically consists of 5 yards of fabric (had about 25" left over on one end), some nanoseeum netting for baffles and 12 oz of 900 fp down.
Jamie - I'm digging the color too. I had my reservations, but I think I enjoy having something in my kit that isn't one of the standard drab colors so common in UL gear. I didn't bother with searing the fabric: I just made sure all fabric edges were sewn over themselves twice or more so that the loose edges were locked away and hidden. I think searing is a pain and the risk of starting my project on fire feels like it outweighs the benefit. As always, looking forward to seeing what you come up with regarding your quilt, sweater, etc.