As far as VB hammock socks go... you can read about them here.
They work for some folks...
FWIW about socks. I found that the weight trade off (and some of you groan about the gram weenie) wasn't worth it. For a 7 ounce sock, the extra warmth wasn't as good as getting a top and/or bottom insulation that had 7 more ounces of down or pad or whatever your favorite insulation is. Add to that, even my breathable fabrics often didn't breath enough. So changing from a 14 ounce bottom quilt to a 20 ounce bottom quilt was more efficient in my experience than adding a 7 ounce (or heavier) sock was, and that extra quilt didn't cause the top of my quilt to have water on it the next morning in all but the VERY cold weather where they would be ice crystals on the inside of my sock.
But I did still want that warm air area for sitting up in my hammock reading or writing, or whatever. I came to the conclusion that what I wanted wasn't a sock, but a head cover, similar to dejoha's HUG. Something I could have a warm air pocket around my head while reading and stuff while laying around in my hammock. I made one out of breathable material and still had to add in vent holes. When you don't need it you can pull it back, and when you do need it you can put it in place. It only weighs about 3.5 ounces.
It may or may not be what you need or are looking for, but it is one idea you can consider.
Garlington Insulator. That dead space under your UQ can be filled with virtually anything to provide added warmth whether it be extra clothing or a plastic bag full of leaves. They were able to use a trash bag with mylar blankets (total weight 6 ounces) down to 13 F while keeping the temperature of their back at 88 F. In the absence of a plastic bag with mylar blankets inside, the sock will still resolve most issues with o poor UQ fit and the associated convective heat loss. While the sock alone will do little in terms of slowing conductive heat loss, it does excel and reducing convective heat loss.
Another item of note. When I have a sock to use, I can get by with less tarp. In other words, the extra weight of a sock can be leverage to provide more benefit than its weight alone provides.
Now that I'm looking at the Garlington Insulator aspect of a sock, I may need to go back at testing it with a plastic bag with a space blanket inside.
I have not really ever considered that sort of application as a sock. I did find that my failed cuben hammock was warmer than a fabric hammock, so much so that I totally abandoned it for a summer hammock solution. Since it's failure I had to decide what to do with the material and decided to go with something like this:
Zpacks cuben poncho groundcloth http://www.zpacks.com/accessories/gr...t_poncho.shtml
When the hammock failed on that hike, I used the body as a ground cloth for a couple of nights until I got back to home. I realized that there might be something to this idea when used with a hammock so I came up my own poncho to those specs with this added use:
The picture shows it over the quilt, but I found that this set up is not optimal, it holds in moisture to the underquilt and compresses loft. What I found worked better is to put it between the hammock and the underquilt.
Obviously this is something new I've started playing with. I haven't tried it in really crappy weather yet, and I'm not sure how I will work it if the poncho has been used in the rain already. But something like this would allow you to add stuff for insulation under the hammock like your Garlington system. It is a little heavier than one from Zpacks would be because it is cobbled together from parts and pieces, but the dimensions are very much the same as a Zpacks poncho/groundcloth.
So, some questions from a nube, is IX insultec? What might SEEP be? Slept out this weekend, snow and about 15, was nice and warm, very little condensation. I like the idea of a thick weather resistant sock. One of the first times I slept out, I was completely unprepared and it was a near blizzard, so I always have that in mind. I use a tarp with my sock but I want to have a stand alone sock when the weather is so bad I don't want to put a tarp up and have it ripped to bits. I guess it's the military in me, I'll take the weight to have bulletproof.
Just received a MM Sock. Great workmanship. I used it for the first time night before last with a low of 25. I had a good bit of condensation. My question for Mac and others, would adding an 8-10 inch hole in the top above my head similar to the HH To Cover be a good idea?
I have made one my self and I have one that was made by warbonnet they seem to help alot. I use a pattern I found on here for a bug net to make mine.