I like them because , it is easier to take care of and get replacement parts. This is also why I like ballbearings and cups.

Sealed is ok but I cannot see the problem to fix it.

The Octalinks do have problems but again not used for street use. I have a messenger bud in NYC who rides hard and I was surprised he rides them and he rides HARD!

Conclusion, easier to maintain and get parts. same applies to my Headsets.

square and tappered can also slip if not maintained properly.

S/F,
CEYA!