On my VAIO Z, I've employed RAID0 striping via hardware-raid. However Level-0 didn't improve any higher redundancy for disk crashes, but otherwise it improve the higher performance for readout sequential.
Then Disk-1 and 2 scores around 520 MB/sec on each, so RAID-0 goes nearly 1 GB/sec!! lol
Yeah it's absolutely fast. Especially on reading apt, calling zeitgeist, and search... VAIO Z isn't only for speed on boot, but also "on running". :)