I had a pair of these before 3M bought them, they were excellent in my application.
It was a WOOT deal before WOOT went to heck.
We've all got different ears, no "one size fits all" when it comes to these -
These fit and stayed in my ears, and were close enough/tight enough of a fit for my helmet to slide over them, and they would still stay in place.
I've never tried the "Skull Screw" tips, and rumor is, these are not as good a quality as they once were.