I have one on my '94 KTM 300. Don't have anything on the front of the other two bikes (I use shark fins on all rear discs). My dealer said that in five years he has seen only a couple of damaged front rotors. I guess that it's better to be safe than sorry, though, and I'm actually considering getting a couple of protectors for the front. I think the plastic protectors are fine; any impact severe enough to bend the rotor through the plastic would probably also go right through the aluminum guards such as Devol's. And if you run the aluminum guards, you have to modify your front-wheel spacers to accommodate the additional width of the aluminum