Asrock is from Asus, it used to be the "lesser quality" boards back in the days, these boards had bad electrolytic capacitor which caused some issues. Nowadays, things are different, even OC records are done with Asrock. The quality increased and as long as the Lanes and timings for the onbard-chip aswell as Slot-bandwith are the same as others with same socket, the difference is marginal to non existence.