The Numark Mixtrack Platinum is a 2 channel (but 4 channel capable) Serato DJ controller with led displays in each jogwheels that show track progression, BPM, track length and more.
The Mixtrack Pro 3 is a budget controller, but one with full-sized pitch fader (very rare at this price range), 3 band EQ and filter, pads to control different functions in Serato DJ and even a touch strip to quickly navigate your tracks.
The Numark NS6II combines many things of recent Numark/Denon DJ controllers (the jog wheels with center LCD screens from the Mixtrack Platinum, the touch-capacitive knobs from the NSVII and NS7III, the dual USB's from the Denon DJ MC7000...) into a convincing offering that should please beginning and experienced DJ's alike.
The Numark NS7III is a build like a tank, has spinning platters with real vinyl on top of them and all the possible bells & whistles to control Serato DJ without having to stare at your laptop screen.
The Numark NVII is fantastic and compact DJ controller for Serato DJ. The built-in screens allow you to focus on your performance and the unit has professional grade features.