I bought a few from Chris Hightower. I recently installed one on a breaker for a player. 25oz if you can believe that. He likes it just fine and he is a pretty picky player re equipment.
They look like a well made tip and the install went fine.
My opinion is that they are as hard as a rock and feel close to phenolic, only legal.
I would have no problem using one for myself and certainly, the price is right. Can't get much better than that.