CompuServe Messages

I have two IDE hard drives, and an old CD ROM drive which I will replace eventually – I have no idea what the interface is to the CD but for discussion purposes lets assume that it is not SCSI. I have an SBPro so could use that proprietary interface to add the CD. Eventually I would like to also add a tape backup, perhaps some more disk storage. What are the advantages for me to move to a SCSI rather than staying with the IDE's and whatever comes with the PC specific peripherals. – Dan