Mod Edit: There are many misconceptions in the statement below, see Silver Snake's explanation further down.
All the slots are for are for additional cooling (more air flow & surface area) and will only benefit you in an instance where you're using your brakes a lot such as a track event, auto-x, racing, et cetera. For a daily driven car they're a waste and overkill IMHO. As the other posters mentioned they'll wear the pads quicker than standard rotors, will typically warp easier since they're not quite as sturdy, and can potentially crack near the slots too thus making them not as structurally sound (although not nearly as likely compared to cross-drilled ones). They do look kinda good though so if that's what you're going for then I suppose they can be worth it then. Just my $.02 
Last edited by Andy W.; 01/05/04 10:49 PM.
