Unfortunately, we haven't reviewed any ASRock or BIOSTAR here, but should do so in the near-future. I've heard great things about ASRock though and typically meh things about BIOSTAR (mostly about their short life before problems occur).
So, the thing is... onboard audio isn't stellar, and if you have a good pair of headphones, you should notice the difference. You might want to invest in a small Xonar card (around the $40) range if you do happen to get a mobo and don't love the sound. Typically, onboard audio changes little up until you get into expensive motherboards that feature special chips (like GIGABYTE with its Xfi, or ASUS with its onboard RoG solution).
Sorry again for the moderation issue!
Intel Core i7-3960X, GIGABYTE G1.Assassin 2, Kingston 16GB DDR3-2133, NVIDIA GeForce GTX 770 2GB
Kingston HyperX 3K 240GB SSD (OS, Apps), WD VR 1TB (Games), Corsair 1000HX, Corsair H70 Cooler
Corsair 800D, Dell 2408WFP 24", ASUS Xonar Essence STX, Gentoo (KDE 4.11. 3.12 Kernel)
"Take care to get what you like, or you will be forced to like what you get!" - H.P. Baxxter
<Toad772> I don't always drink alcohol, but when I do, I take it too far.