Here's the rig we used:

Intel Pentium 2-300 and 450 CPUs
Abit BH6 440BX Mainboard
Goldstar 128MB PC-100 SDRAM (Chip Part# GM72V66841CT-7J)
Matrox Millenium G200 16MB AGP
Adaptec 2490UW Ultra-Wide SCSI Controller
IBM Ultrastar 9 UW-SCSI HD
Diamond Monster Sound MX200 3D PCI Sound Card
Plextor SCSI 32X CD-ROM
Win95 OSR 2.1

Test Conditions and Specifications: All tests were run a total of three times with the results averaged to determine final score.

The results are pretty clear, UW-SCSI is impressive even on mid-range machines. The Ultrastar 9ES performs very well, almost as well as its costly 10,000rpm big-brother, the 9ZX. About 10% in rough performance separates the two drives, but the 9ES costs $500, while the 9ZX currently runs around $620. Whether or not the 10% speed difference is worth $120 is debatable. What is not debatable however, is the fact that IBM is really taking the competitive hard drive sector by storm this year, and shows no signs of slowing down.