The benchmarks of the new 150GB raptor are pretty impressive.
The one I was looking at put the drive in the middle of the pack with Enterprise SCSI Drives, even 15K drives. It also out performs Seagate Drives in RAID 0.
I'll try to find the link and edit this post later... I think it was at www.storagereview.com (I think?)
If you can stomach spending $300 on a 150G drive... It will more then pay for it's self in performance...
There is another drive the RaptorX with a clear window on the drive. I wouldn't buy that drive unless I had one of those arcylic clear cases, with the drive mounted sideways so it can be seen from the side. "Otherwise, it's about as useless as tits on a bull."