i5-6600 + DDR4 or i5-4960k + DDR3

[nigsia]

I'd like for people to debate on this topic, since I don't really have a strong opinion on any option and I'd like to read yours.

A few questions/ideas I've got:

• 
  - Is DDR4 worth?
  - Building with the 1151 socket might be a bit more expensive, since it's relative newish. Worth?
  - I think the comparison 6600 vs 4960k is a legit one, since both are similar processors (without overclocking), one being around 2 years older from the other one. Opinions?

What do you think?

 

[CTurbo]

Since overclocking is a wasted investment, I would choose the i5 6600 in this scenario. ddr4 has nothing to do with it since it doesn't REALLY offer any advantage. I would not be above starting a new build with an i5 4590 though.