I had Diamond G 4 degree key first and raced with it many times with no problems then upgraded to there 6 degree key and just returned from prerunning the Baja 500 and had no problems. The reason I used there key to start with is it is the only one stamped from tooled steel that I know of. If the flywheel is installed correctly there is very little force excerted onto the key.
Tonto

 

Tonto57, did you notice any gains at all going from 4 to 6 degrees?

 

Yes there was a gain in mid and top end performance with the 6 degree key kiss of death not huge but noticable. I just picked up a Brute Force and installed the 6 degree key and waiting for the dg3 to arrive to go back to Baja for a long weekend. I will let you everyone know how it does.
Tonto