Well my VelociRaptor came in yesterday. With HD Tune 2.55 I get about 98MB/s average transfer rate, burst of about 150MB/s and seek of 7.3ms.
I see about a 20-25% improvement over my old 150GB Raptor.
I doubt whether it's really worth it to put down $300 for a 300GB HD, but then again this IS the fastest thing out there...