Scott,
all I know is that the XD9 can be connected to a PC via a serial cable and will respond to the Ketron file transfer program just like the SD1.
Once a flash card is installed on the XD9 you will be able to upload sounds. Now that I think of it, the XD9 can accept a HD as well, so I wonder how this would cost compared with a flash card. I seem to remember, however, that the flash card comes already loaded with sounds.