hi,
I have 2600k,3770k and the 4770 haswell.To be honest there is not much difference in clock speeds if that is what you want.The difference is the size of the chip and its structure,it can do more with less.The 4770 uses less volts but on overclock I would recommend a water cooler they do run hot.
For a really good comparison I suggest you look at tinytomlogan videos where he runs through all the ins and outs of the chips.I run the 3770k no overclock but I set the cpu voltage and the ram in bios so it runs stable,auto voltage is a no no.Hope this helps
stewart haworth