IDE/ATAPI interfaces are more user friendly and becoming more popular for CDRom, CDRW, DVDRom, and DVDRW drives. Sony actually has a tape drive out now that has an IDE/ATPI interface. The difference? Speed really and that's about it. IDE/ATPI like I said is more user friendly and easier to understand/install for the average home user where as SCSI can seem complex.
"Astra non mentiuntur"