Many folks report good results, but I have had poor results with cross-drilled rotors on 2 very different vehicles.
I never had any problems with warping, however.
The problem was premature wear on the (center) swept area at the diameter where the holes are, and slower wear on the inner and outer diameter where there are no holes. Eventually, the surface was so uneven that the pads were only contacting a small fraction of the swept area.
My current theory is that the concept is fundamentally flawed, at least for street use.
Perhaps my ugly pictures are still in the archives.
Never again for me...
Best of luck.
1986 300E 5-Speed 240k mi.