Does anyone have any knowledge or experience with rotors that have been cast with holes in them rather than the rotors actually being drilled?

 

You mean like the factory parts? I have them on my S2. They work very well.

 

The cast rotors are less likely to crack, when holes are drilled into a normally cast rotor you create stress and all around those holes you are likely to get cracks.

Cast rotors don't elimiate this problem and you can still crack them, but the cast holes tend to be stronger and I belive that cast are the only ones available from Porsche and Brembo.

Are you going to notice a difference between the two? Odds are no, do the drilled rotors look better, well I say yes and so do a lot of people, but ultimately it is up to what you want to spend for rotors and how you use them.