Okay so I have a mixtrack pro at the moment. i feel i can being doing so much much. i feel i need an upgrade soon. so what does the numark n4 have that the numark mixtrack doesnt? why should i upgrade to the n4? and if i shouldnt upgrade to an n4, then i really want more control over effects. so i want to get the kontrol x1 to go with my current numark mictrack. what do you guys think? btw i use traktor if that helps