I got a head sock for my first race. None of the other drivers on my team got a head sock. My main reason for the head sock was to keep my ears flat to my head when I put on the helmet. I had a hell of a time pushing my ears back up flat to my head with the helmet on. So, if you have ears that stick out, the sock is nice. Additionally, my helmet had the least amount of sweat as the sock absorbed most.
'86 E30, '09 Stafford Aug, '10 CMP Feb, VIR Apr, Summit Jun, CMP Sep
'11 CMP Feb, Rock Mar, Charlotte Apr, Summit Jun
'68 MGB '11 NJMP Apr (winner IOE)