The remark about "blowing their money on SCSI"'s was, well, stupid. The short answer on your drive needs is that it depends.(posted 9015 days ago)Are you working with a firewire card and doing native DV editing? If so, not much speed is required, and you can start enjoying the savings of non-scsi options.
BUT say you need a professional system with real-time effects that handles a variety of video formats... like a Matrox Digisuite system for example... then not only do you need SCSI drives, but you're going to need them in striped sets of 3-4 drives each.
You can start entering into the zen of performance benchmarking and find yourself memorizing sustained throughput rates of different drive makes and control formats. Then again, you can just first decide on the video hardware you're going with and call their tech support to see what they recommend--quick, dirty, and probably your best information.