As an upgrade it's pretty bad value to more from one quad core to another and once you roll the dice on overclocking you could even find it's a downgrade. If it was a choice between the two then the i7 would make some sense depending on price.
I would bank the money and hold off until Zen or Intel get their act together and move desktop chips to 6 and 8 core chips. Something that I feel they could have done with Broadwell and Shylake.