Last night I had the SD5, Midjay and PC all hooked together. I could take a pattern from the Midjay, which appears as an external drive to the PC, and load it onto the hard drive of the SD5 without ever saving it to the PC.
I was able to control the MJ from the SD5, though I can't see a benefit for that unless you want to incorporate loops or WAVs with the SD5 style.
Just experimenting.
DonM