Cheap but efficient DJ controller??

I am a newbie and am willing to buy a DJ controller. I have read an article about the Best Budget DJ Controller, and I found that Traktor Kontrol S2 is an extremely affordable controller which people on a budget might prefer to buy but now I am confused between Traktor Kontrol S2 and Traktor Kontrol S3. S3 is out of my budget but if it is better than S2, should I go for it or simply focus on my budget and buy S2? Can someone guide me, which is the best of these two?

 

These can be said to be the same controllers, but I would prefer to take 4 channels, because if you sometimes want to use the third channel or connect other controllers from Traktor later, then S2 with two channels will be limited