My key notion of "helmetosity" is how readily pollsters rank a team higher than it otherwise would be. This doesn't have some magical cut off in my opinion, but shades of gray. When a program like Boise State has some success, folks find it a lot easier to rank them 3-4-5 spots higher than otherwise, if not more.
I don't think pollsters put much thought into rankings, especially once they get below about 10. They read a little bit and see that Team X has Y starters returning off an 8-5 squad last year and figure they will be around 12th, or 14th, or 18th, who really cares? It's not as if there is accountability for anything.
So they get to 20-25 and are throwing darts, but they are going to find it easier to rank a "Georgia" 20th than they are a Kansas State 20th just because of the helmet.
I doubt they bother to think much about an Alabama or an Ohio State other than a very cursory "Who's back?" glance, and then they go top five every year. Until their helmet loses luster. Then they start out 12th. Until the luster really tarnishes.