> As far as I know they are functionally interchangable. Creative doesn't make a distinction on their web site. I think the difference might be that one is an OEM version and the other has a Soundblaster label on the front.
> You can also use a CR-562 which is the same drive without the digital audio out.
> There are also some panasonic oem drives branded by other companies that will work. The important thing is that it needs a MKE proprietary interface. In a pinch you could even use a 1x MKE drive.