I dont know how fast the Barracuda runs, But the Raptor drives are faster then normal drives, but is it worth it? In my opinion its not worth the extra money for them. I have 2 Raptors and yea its faster, but not by a whole lot, In a benchmark its much faster then a standard drive, but in normal everyday stuff, you probably wouldnt even notice the difference. Just my opinion tho.
Now i do have the Raptors that where prior to the Volciraptors, but i believe as far as speeds and response times they are the same, I just think the Vraptors have more storage space.
On average with my drives as single drives, they run at about 80MB/s read and write. In raid 0 its about 160MB/s
i7 2600K - Asus Maximus Extreme-Z - G.Skill DDR3 2133 CL9 - MSI 5870 - Corsair 1200w PSU - 2 x Western Digital Raptors Raid 0 - Swiftech Apogee XT Water Block - Swiftech MCP655 Pump - 120mm Quad Rad - Windows 7 - Ubuntu x64 5311Mhz Validation