I went from a much lesser CPU, Phenom II X4 820 to the Intel i7-4790k. Surprisingly the jump isn't as obvious as you would think. In general use it feels about the same as my Phenom. I did some before and after benchmarks and that was the only real way to tell if it was faster or not. It wasn't until I loaded up some games that the upgrade became very apparent.
Don't expect it to blow the doors off but it will be noticeable in some applications like games where you will get a higher average framerate in most cases. Do some before and after benchmarks to see how much of a gain you get from it.