I haven been using a SSD drive for a month and i LOVE IT ! no writing noise when running in shattath, got quite a huge boost in performace.
Upgrading from 4-8GB ram and getting Vista 64 was a even bigger jump in performace, i can run around in shattath without loosing follow now

Btw, using a lowlevel Geforce 8800 gfx
No brand motherboard (crap one).
Onboard LAN
etc.