Disclaimer: I work at EE, etc.
I'm actually 6'2", almost 6'3" and use the Regular length. If I'm laying flat on my back and stretch out I can put some pressure on the footbox, but when laying normally, esp. when side sleeping, it isn't really an issue. The only time I go with the Long length is for very cold weather trips when I need to keep a water bottle in the footbox to keep it from freezing overnight. I obviously don't normally use it to cover my head. I always feel kind of smothered when I try, so using a Hoodlum is a must for me in any sort of cold weather, or just a beanie when it's a bit more mild.
For any of the others on here who do use our quilts over your head, out of curiosity, do you normally end up closing up the top at all, or do you just leave it opened up?