Nobody's really speaking up, but when I was researching my rotors I found a few threads where this was mentioned. I chose SP Performance's "diamond slotted" design because the holes' edges are tapered, which should be less prone to having little rocks get stuck.

FWIW I'm pretty sure this is the exact rotor that Tone was using for Rally racing - he was one of those who spoke very highly about them when I was asking around.

I don't have them installed yet, so I can't give you much of a first hand review.