I have drilled and had no issues. You want a serious brand for drilled, not random ebay crap (not that you should get random crap for blank rotors anyway, but even less so). In particular, you don't want a good brand (blank) rotor that has been drilled by some random jackass on his man-cave drill press, like some ebay deals feature.
I have the stoptech, they look great and have been solid performers so far. The braking performance is very similar, I noticed that brake fading has been improved, but I compared with worn out OE rotors, many parameters beside drills could explain the improvement (first, the new rotors being thicker have more thermal inertia).
They have not cracked in the 8k miles I enjoyed them, and I am heavy on both pedals. Not recommended for track/autox use, as drilled rotors have been reported many times to fail in that context.
It is generally admitted that drilled rotors offer no performance benefit for street driving, and are unreliable for track, so that makes them cosmetic upgrade only.
Last edited by Meeni; 02-07-2013 at 02:28 PM.