I remember talking to Pan at the Rogers Hangout last year. I agree with what he is saying. The right tarp will block all the wind and airflow you need. I played around with hanging my rain jacket over the ridgeline over my head. It does a great job of trapping in the heat. Condensation can be an issue.
Given the tarp size and end covers are correct to stop the wind, I think heating the air you are breathing in is the biggest benifit to the hammock sock.
Is that too much to ask? Girls with frikkin' lasers on their heads?
The hanger formly known as "hammock engineer".