The Native Instruments Traktor Kontrol S2 MK2 is the successor of the already great Kontrol S2. The jogwheels have been upgraded, the controller supports Traktor IOS DJ natively and the overall quality feeling is improved.
The Native Instruments Kontrol S5 is the smaller brother of the Kontrol S8 and lacks the hardware mixer, DVS capacity and the per channel line faders of the S8. But it's more compact, and makes up for the lack of said channel line faders in a smart way.
The Traktor Kontrol S8 made a lot of noise when it came out in 2014, almost 2 years ago. The lack of jogwheels, the build in screens, the 4 line faders per deck to control remix decks.. It was quite different from other controllers on the market. 2 years later the S8 still is relevant, with the arrival of Stems and the Sequencer function it becomes a true performance machine for the creative DJ/producer.