The onboard sound is OK, a RealTek chip I think.
There is no PCI slot, so make sure the Shuttle has everything you need. It's got onboard networking, USB2, firewire etc.
You've got Crossfire slots but no support for SLI. So you're stuck with 1 NVidia card.
Oh, and you'll need a USB keyboard, no PS2 port. That caught me out and my Old IBM keyboard now gathers dust.
The rearmost SATA lead is a gnats whisker short and had to be rerouted to reach the HD on mine.
Apart from those niggles I like it, the fanspeed options in the bios are ace and it's got basic overclocking options though nothing fancy.
The next few weeks should see mine watercooled throughout which is gonna be a tight squeeze.