Hey Jerry
You can use SD1 styles with Midjay witout any problems.Except the ones came with EXP Pack from AJ.Those ones needs a little tweaking becouse of missing instruments.
You can copy SD1 styles in any folder you like, I put them in "Styles" folder, in a new "SD1 styles" directory.Midjay HDD strucure and operations are the same like a PC.