I have an S4, I dont have an answer for ya but I do have some questions :)
what did you use to connect the drive to the S4, a Juiced adapter or small converter cable?
if the juiced one, are you able to get the s4 to work on the CDJ via the usb cable or you have to go through a wireless router?
which wireless router are you using?
I am debating this as a backup and want to run it though a 5ghz router, we shall see