In many ways this setup is a hybrid of the above two, with an added old school flavour. Native Instruments' Kontrol S4 (above) with Traktor Scratch let's you plug in two turntables with timecoded vinyl (true four deck control!), and Numark's NS6 simply lets you plug in good old turntables - the perfect greedy mix of digital controllerism and vintage tactility.
This arrangement might be favourable to those dyed in the wool turntablists who are curious about dipping a toe into the digital realm, or a good blend between technical tomfoolery and good old visual performing. Audiences still relate to the DJing with records concept much more than the sinister button pushing of controllers; mixing it up this way allows you to garner faith from the crowd, yet bedazzle them with hot cue trickery.
More hardware is needed if you just have a controller, but if you are coming over from the analogue world this is a great entry point.