Ok sorry – The S4mk2 is iPad/iPhone compatible/plug and play with Traktor DJ, and comes with a cable with the square end that jacks into the S4 where the USB cable goes, and it has a 30 pin flat connector that I take it was the old protocol for iPod/iPhone at the other end. The new iPad/iPods must have a new connector roughly 5mm across (the old one is ~15mm). NI recommends an iPod5, but makes no mention of how it would connect to the S4.
I’m under the impression hooking the iPod up to the S4 will give me proper cuing and nudging through the external soundcard.
If I like Traktor DJ on my iPod, I’d consider getting an iPad4 and/or a MacBook Pro for metadata syncing etc.
Hope that makes more sense.