I have 9 years experience in cross-drilled and slotted rotors under normal street or heavy street driving. There are tremendous difference between cross/slotted and stock rotors under any braking condition. It is very evident. I used same pads going from cross-drilled to stock (because I was selling the car and didn't want to spend money for other people). The grab is weaker with stock rotor... feels like slight fading... doesn't have intense grab as cross/slotted rotors did.

Now I use only slotted wherever I can. It is worth every penny especially in summertime where heat is intense. I always use MetalMaster with slotted or cross-drilled. Now I am experimenting with ceramic.

I like the grab of metalmaster better than ceramic... ceramic feels more like regular pad but alot quieter than metalmaster under intense braking but with no fade. I think it is waste of time to use regular pads with slotted/cross rotors as most of you mentioned you can't feel any difference.

As for between cross and slotted... you can't tell that much difference in performance... cross might be slightly better but it is difficult to tell. For the 7 years I had that cross-drilled... never did it ever cracked... It was Zimmerman made in Italy. Only caution is do not wash car when hot... cold water and super hot rotor is sure fire way to warp it... possibly crack it if you went from highway to car wash immediately... as in automated. Again... never in that 7 years did it ever cracked on me and I even had the rotor cut once... However, cutting a cross-drilled rotor is not advised... it warp as easily as any cut rotor.