This unit is simply an amazing design. Best SFF ever, and I've tried them all.
Mine has the following running 24/7 on stock volts:
AMD A64 4000+ San Diego @ 2650MHz
ATI X1800XL running @ 540/1200MHz
OCZ Gold PC3500 2-2-2-5, 1T @ 442MHz
Dual WD1200JS SE SATAII drives in RAID 0
Plextor DL DVD Burner
Mitsumi Floppy
8 in 1 Card reader
Wireless Lan
Firewire & USB in front and back
And I still have an open PCI-E slot.
Even with all of this the Shuttle runs very cool and quiet, even with cool and quiet disabled. Does your SFF do 31000+ in 3DMark2001 and 8000+ in #DMark05 with no tweaks on it's 24/7 settings with all virus/spyware programs and services running?