TweakTown has posted a review on the Western Digital Raptor X harddisk

Hard drives are vacuum sealed from the factory to prevent the entry of foreign matter on the drive platters. When you open a drive you allow air, moisture and foreign matter into the drive, which results in bad sectors, data corruption and eventually, rendering the drive totally useless. The Raptor X has a factory built in window allowing you to view the drive platters and heads at work, which is a much safer option than doing the mod yourself.

Western Digital Raptor X – Return of the 10,000 RPM King