I would only consider SCSI if I was a professional and truely needed that extra performance.
ATA/66 is really the best bang for the buck these days, falling right in the middle of today's typical SCSI speeds of 40 and 80MB/sec....at a fraction of the cost.
I recently purchased a 9GB SCSI drive for my work server at a price in the $300 range. In that case SCSI was truely needed. But for that cost I could have purchased almost two 20GB 7200RPM Ultra ATA drives for my home machine.
Recording requires a lot of space and a lot of speed. As EIDE continue to decrease in price and increase in speed...it's really a great way to go for the home studio; and in many cases even the semi-pro to professional studio I'd imagine.
To go the ATA/66 route you'll need a machine with an ATA/66 controller, preferably on the motherboard, and the latest greatest chipset (e.g. Intel's i840) to really see the benefits. Plugging a 7200RPM drive into a standard EIDE controller isn't the correct solution.
Many mobo manufacturers today offer ATA controllers right on the motherboard. Check out
www.abit-usa.com
As Emeric mentioned, Quantum makes a really nice drive. Avoid Western Digital like the plague. I've also been noticing that Maxtor is making real cheap 7200RPM drives...about $129 for a 13GB. Seagate also has great prices at times. I've used both Seagate and Maxtor drives in the past and was satisfied with both...and am currently using Quantum.
Slackmaster 2000