They are 2 totally different controllers.
The NV is a mid-range controller (500 to 600 bucks) we have yet to see how well it is made and it has some screens on the controller which show you the exact same thing as your laptop does. Which I would consider not useful for me, as I only look at my laptop when selecting tracks mostly or at the waveform for scratching. Both times the screen on the laptop is better (I can compare as I have played with CDJ 2000 Nexus players and I do not like to look at their screens either). Honestly I would have rather hoped for an upgraded NS 6 than the NV, but due to people loving new features I am sure it will find its buyers.
The DDJ-SZ is a pro grade professional controller with full size CDJ player control units and a DJM style mixer with hardware effects and DVS function. You can even hook up 2 laptops to it. Feature, size, weight, controls, build etc. I would say it is a totally different league than the NV and you cannot compare them. Personally I would not buy it either as it is way to heavy for me, but if you want the features it has them all.
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