Once upon a time, the Western Digital Raptors, with their 10,000rpm spindle speeds, ruled as speed king of the hard-drive landscape. These days, SSDs destroy them without blinking.
The positioning of the Velociraptor, the heir to the Raptor throne, is tricky these days. Speed freaks have mostly taken to pairing a modestly capacious SSD with a large mechanical data drive, and the Velociraptor fulfills neither of these tasks.
It is of course cheaper per GB — at the time of writing, an Intel 520 240GB SSD can be had for around AU$269 (AU$1.12 per GB), whereas a 1TB Velociraptor goes for around AU$309 (AU$0.31 per GB) and a 500GB version goes for AU$195 (AU$0.39 per GB). So perhaps it's position is one of a compromise drive for those who still can't justify an SSD, but still need a bit more space.