While it's not a terrible board, Biostar is a budget manufacturer. I have used many of their boards and even use one in my own HTPC and they have been great but since you seem to be going for a pretty high end machine (Z87) you would probably be better off with something from Gigabyte or ASUS.
While the enhanced audio may be slightly better than the standard onboard stuff the difference won't be huge and isn't really worth compromising the rest of the system for. If audio quality is important, you'd be best to get a separate PCI-E sound card.