Depending on the situation, they might; however, I would not bet on it. Slotted rotors help clean the pads more than allowing them to cool down with each pass of each slot. The front discs on the STi are huge, not just in diameter but also in thickness. The internally vented discs at that thickness should have been enough, if the stock pads were a little more heat resistant. I think the front rotors' size and and the weather being quite cold at VIR, the R4S pads held up. Otherwise, with the speeds that the STi achieves, we are not going to take a chance with anything less than track pads on track days, R4 or Hawk Blue.
For auto-x, R4S is plenty enough, and even the stock pads should do just fine.