The big issue in the past was cracks between the holes. Don't remember hearing anything about slots having issues, but might have missed it.
It could make sense though, by thinning out the rotor especially if the producer went too deep.
I have had more standard rotors warp on me than drilled and slotted, but that's a fairly limited gene pool to make any real hard and fast rules about.
When the rotors are actually "drilled" as opposed to other methods, the cracks seem to form more quickly. If they are cast in during manufacture, or broached after it's much less of an issue.
But in most cases for most street users the cracks do not seem to cause trouble unless they get really bad. In racing of course, I've heard of rotors self-destructing, but seen standard rotors do that too, and don't remember hearing that the modifications were always at fault.
Even the manufacturers say that slight cracking of the surface between the holes is not a sign of imminent doom. Truck rotors likely get put through more heat and load under normal conditions than a lighter vehicle would though, so go with your gut. If you're not sure you need the added cooling with your heavy and vented rotors, keep 'em smooth.
If you experience fading regularly and have tried different pad materials, I would think drilled and slotted, or just slotted, might be a good next step.
And yes, the F1 stuff is apples and oranges nowadays especially. The old ones were often drilled and slotted, but with the new carbon ceramic rotors, it's not the same thing. Probably not even an option to molest the friction surface. Might cause stress risers and major explosions.
That's some pretty high-tech stuff though, so you never know what they're going to come up with next.
Drilled and slotted street rotors are a very common modification. More now than ever, even by some big name companies. Centric and Raybestos for two. Of course companies like Wilwood and Baer and others too.
If they're causing more trouble I'm sure they'll get called out about it and ruled out of existence either by the market or government.
As always, use common sense and if in doubt, don't do it.
For now I trust them for my particular use. I only install them when the regular ones wear out though. Don't like wasting perfectly good parts.
Paul
