Atom 330 is a GREAT basis for a micro-server, but for a desktop, you will be pushing P4 performance, not more. You may be disappointed.
Could you run some benchmarks on the Zotac please? Please see here:
http://forums.techpowerup.com/showthread.php?t=82785
I am fully aware of how weak Atom is.
What benchmarks ? I didn't build it to run benchmarks though.