A couple of months ago I went one track session too many on my front brake pads and messed up my rotors. So I called a respected vendor and tried to order the identical slotted rotors that I was using. The vendor said he did not stock the slotted rotors and the plain rotors where what I needed, and the the "slotted thing" was old technology. Now just after four track session these new rotors are starting to show heavy signs of "ribbing or scoring". When I asked some track rat friends for there thoughts they said maybe pads but slotted rotors prevents this condition. I did not think pads where the issue as I had installed new Wilwood PolyMatrix "B" pad with the new plain rotors. A few "google searches" later I found this article on this EBC Brakes web site: EBC Brakes | Rotor quality and bedding in new rotors article ( I have copied it below). Rotor surface finishes such as slots - what do they really do... Plain rotors cost less and rotors without slots are less money to buy for sure but can exhibit some problems. Firstly the phenomenon known as rotor galling or brake rotor ribbing or rotor scoring happens everyday with the world being full of fairly soft cast iron rotors. The better the pad the more likely a plain (not slotted) rotor will suffer rotor ribbing. The picture below shows a typical normal rotor that is suffering from rotor ribbing. You donâ€™t throw this rotor away, it is not ideal but it is not a safety issue either, you just have to live with this condition unless you want to upgrade to a slotted brake rotor. Slotted rotors have a major benefit in smoothing the brake pad gently as it wears through its useful life, the slots do NOT cheese grate the pads away surprisingly enough and lifetimes can actually be BETTER on a brake pads used against slotted rotors than one used on plain brake rotors because the pad runs cooler and more efficiently. This is what a slotted rotor looks like after 10,000 miles using the same pads as the plain rotor in the illustration above. The key benefit then of a slotted rotor, is smooth and parallel brake pad and brake rotor wear. EBC make a drilled and slotted rotor with its GD series and these work very well on heavier and faster cars and are a big favourite with light truck users. EBC does not like the aftermarket idea to cross drill rotors, these can crack, if you want to see this for yourself click here. A search of Wilwood web site revealed thoughts that where less direct, but they do say, " For most performance applications, slotted is the preferred choice." This quote is from: Wilwood High-Performance Disc Brakes - Frequently Asked Questions (FAQs) I am especially concerned with this condition as I need to swap back and forth from track to street pads and when it is time for new pads they will not bed in easily. So the question is the EBC article correct or is the respected vendor point of view the most current?