The built quality and the stability of the mobo are aspects that should be taken in mind. The speed is not all. ASUS is a much better brand.
If you want a mobo, I recommend you to go for ASUS, GIGABYTE or EVGA.
If it is not possible, you can go, as a second option, for DFI, INTEL (intel cpus only) or MSI.
The only reason fo going for an ASRock mobo is the price.
Anyway, This is just my opinion.