as title ^^

 

Grooved imo

Drilled discs tend to crack

 

I've run drilled for around 10 years, you get small cracking radiating out from the holes, but no issues, only had one crack open about 1mm, also had 1 disc break away from the bell part that was not grooved or drilled.
I'd go for a combo, dimpled(not drilled) and grooved, and ebc yellowstuff pads, work from granny wagon from stone cold to chav racer high temps.
tabetha