If you go and have a read over on the XS forums, they have been having solid results from it too.
Had a chance to play with it a bit more now. The BIOS is very forgiving when trying to overclock too much.
The uGuru has really been improved too. The interface is much better (BIOS).
Gerrard - The RAID issue has been fixed providing you flash with the latest BIOS that I was on about above