W204 drilled / sport discs

[buggalugs]

I am looking at replacing the front discs on my 2008 C220 CDi, and would like to use the drilled ones because they look cooler. The Padid ones have got the nice anti-corrosion coating on the bell too which is nice. As far as I can see from comparing the specs for drilled/undrilled ones they are exactly the same except for the cross drilling, but I read elsewhere that they can't be swapped, but there was no explanation why...

Has anyone gone from undrilled to drilled, any probs?