I let mine curl around my entire neck a lot. Blackback is my largest male ball python,and he is around the four foot mark now I think. He rides my neck a lot. Sometimes he does clamp down, especially if he slides around. I have not even come close to passing out. And you are right about the unpeeling them off your neck, it is really easy to do.
The only ones I do not let on my neck are a few that are really high strung, and I worry about them biting me in the face. Still not worried that I will get strangled.