Drives are drives these days. In the desktop market, it's Hitachi, Seagate, or Western Digital, and all are comparably priced with similar warranties and performance charactersitics. It's only silly stuff like this file sharing limitation that separates one vendor from the next.
And what's with all the "SCSI's dead" talk I keep seeing on Amiga and Apple sites? Seriously, SATA is still playing catch up to features SCSI has had for years. (We'll stay aware from FC and other options for the moment.) Primarily though, I think the differences are akin to what Intel, AMD, and others do with chips. The good parts go in the SCSI drives, and the good-enough parts go in the ATA drives.
Trev