Mainly because I want to build an all SATA system .... the motherboard I am buying has 8 SATA ports so I figured I better use at least 4 of them to justify the cost. I've been told that the drives can't match the SATA throughput, so they offer no real advantage, so basically I'm doing it for the satisfaction. If I can't find a SATA drive at a cost near the price of a regular drive, I'll settle for round IDE, but if I can have SATA for an extra $20 or so I'll do it.
( I have found an MSI CD-RW SATA drive that must have been discontinued, and BenQ was supposed to release a DVD Dual Format Dual Layer SATA drive but I cant find that anywhere. )