ive used them all. never had a problem with any color rtv. but i like gray for some reason and i seem to always have some. lasts a long time anywhere i put it.
never had a problem with S&B filters. i have 3 sets that are 7 years old that are still good. Just bought another set. worked perfect on 2 rides so far. maybe im just lucky.
also it looks like these are what fast is selling as well.
i like noss first then pd, I have both. But on the chariot the inside cooling jackets are lil holes instead of full size like noss or pd heads. = possibilty of less flow id imagine.