Reply to VCI-400 SE or Konrol S4, really need advice

Would like some advice from people that have used either the Kontrol S4 or VCI-400 SE or both. I had the pioneer 350 setup that I used with Traktor but sold it as I was not happy with simply just mixing and feel myself leaning more towards the controllerist side of things. I sold it with the intention of getting the Kontrol S4 but after recently watching DJ Tech Tools video on the VCI-400 SE I thought it was the perfect piece of kit I was looking for. The only problem is that it will cost me an extra