Unless you are making money with your CPU, I don't think so. Yes the 6700 is 15% or more, more efficient and you should be able to overclock it as well or better. I just don't think that the $700+ cost of cPU, motherboard and memory, plus possible OS reload is worth it. Even if the i7 7600K dropped right in an LGA 1150 socket, with no other change, it would not be worth it for gaming.
If this is a money-making machine than 10 - 15% more gold is a good thing and you will get the cost back quite quickly.