I am one of those that put the Goldwing rotors on my IS. 3 years ago when I replaced them, they were $100 less than the Valks. Now I hear that the Valks are cheaper.
The minimum thickness for the Valks is 1mm thicker than the Wing. The Wing rotors are 1mm thinner, but they stop a 800 lb Wing and I figured they would stop my 800 lb Valk.
Buy the Valk rotors.
Hay

Jimmyt