Well, clearly all NI gear works well with Traktor software. The distinction between an all-in-one controller and a modular setup is pretty obvious, even not taking the jogwheels into account.
If you think 4-channel mixing is something you’d want to move to quickly, I’d consider a 4-channel/4-deck controller right off the bat.
Going with Traktor software, getting NI gear for it is a solid choice. NI are moving firmly towards the “our software really only works well with our hardware” corner of the room.
If you are familiar with DJ gear, I think my preference would be an all-in-one controller rather than a modular setup.
These choices are highly personal though, and without knowing a bit more about your goals and what you want to achieve and why you picked Traktor as your preferred software, it’s hard to really advise.
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