ASRock… the doubt offends :osvaisacagar:
Asus as a brand is overrated... it's not a bad brand but it has hundreds of ranges and models... if you want something really cucumber-robust you have to dig deep into your pocket with motherboards that you pay a pretty penny for or extras.
ASRock barely includes extras but the motherboard is of quality and very robust except for the low-end ones.
Then they have the specific range for OC but there aren't any big differences... isolation and the possibility to modify RAM Timings from Windows... the rest of the circuitry is similar or identical to the Extreme range which is the most interesting.
The only gripe or complaint that people usually have is that the UEFI of ASRock is a bit simple-Spartan compared to those of manufacturers like Asus or MSI but that's something they are improving even though it's not that important.
The ones I do recommend avoiding are Gigabyte and EVGA because lately I've only read bad things and problems with immature BIOS... in any case it's always better to be informed.