I never really thought about my cock head until receiving comments about it on this site. In my case, it seems the size is proportional with the rest of my cock. I knew my length of a little over 8" BP was uncommon, but I hadn't realized until recently that the length of my head (about 2") also seems equally uncommon.
Width-wise, my girth is large but not huge - and when fully hard the head is the same girth as the shaft (neither tapered nor a mushroom head)