I wear the sportsman sliding tether model of Hans, both road and circle track. The only time I notice it is sitting in grid waiting, its a bit uncomfortable on the shoulders. On the track, I never know its there.

Best thing about a head and neck restraint is that it holds your helmet up when you fall asleep, allowing you to nap comfortably- a worthwhile situation when you are racing after a group of late models who are trying to set the record for number of cars wrecked in one feature.