Question:

If you have 2 or more SATA 3 HDD's (spinning platter type, not SSD's) and you RAID 0 them...would you gain any benefit in writing / reading speed than using SATA 1 or 2 HDD's in the same configuration?

Sata 3 (600) only shows performance gains over Sata 300 (sata 2) when using more than 4 drives on a good controller.
newer chipsets may show better as they come out, and firmware is updated.

the best thing about the sata 600 is the 64meg cache. if buying new why would you not buy them..

sata150 (sata1) should not be a consideration at all other than back up.

Scott
ADK