It depends on your needs. The Asus has USB 3.0 headers for a case that has USB 3.0 front ports. Also, the Asus has 6 SATA ports as opposed to 5 on the AsRock. However, the ASRock has an eSATA port which could come in handy if you have external drives you need to connect. The Asus has a 3 year warranty as opposed to ASRock which has 1 year warranty. Other than that, pretty much the same features.
If it were me, I would probably go with the Asus. But I don't think you would go wrong either way.