depends. do you already use them with timecode? and what software?
If your more of a scratcher then I suggest using serato and the NS6 if you are really considering this trade. If you are a serious scratcher, and you still want to use traktor, I wouldn’t do the trade because the NS6’s jogs are poor when used in traktor. And the s4 is one of the worst controller’s for scratching.If scratching isn’t something you want to do too much and you want to really use effects and cue points effectively in traktor then trade for the s4. But your best thing if your a traktor scratch user is stick with what you got.