I installed these on my 06 YZ450F. After seeing where my boot was scuffing the CF guards hard, I realized they are protecting my frame from such damage, so I would recommend them based off of that alone.
BUT!!!! When I removed them to remove my sub frame, they are putting this nasty wear mark on my frame. I was really upset that I never thought of this happening. My recommendation is if you are interested, maybe find a way to put a rubber grommet behind it or some sort of padding that won't wear on your aluminum frame.