If you mean a compression plug, then they'll work with all type steerers.
The advantages are: No need to hammer it in like a star nut; lighter than the headlock; easily removable for the crazy weight weenies; able to be "hot swappable"... not that there are headset tightening parties, but if there was, it could do it... as long as everyone isn't running star nuts and no one remembered to bring their compression plugs. :lol:
The only disadvantage I've encountered is that installation (of some) can be a pain (the good ones have a regular style top cap and an aluminum retainer that keeps everything from falling too far into the steerer). The headlock seems to be the most secure connection, altough for XC I think it's overkill.
And what are my thoughts on compression rings? I'll never use another star nut again.
