They are the BOMB! I have the header coating on several cars. It's the only coating I have seen that absolutely will not flake and burn off. It's not smooth like other ones....it's textured like medium sandpaper, which some people will not like. It comes in white, but you can paint over it with any color you want.
The headers on my GN were done 5+ years ago and they still look like new. I don't work for Swain or get any endorsements, but I challange anyone to show me coated headers as old as mine that look as good.
If it wasn't for the dang TR oil leak, they would have no deficiencies at all.
I have the piston's on my TTA motor coated but it has never run