But then I won't be able to OC much. Should I really?
If it's the same price, 4790K is the better option, even without an OC. Out of the box the Xeon is at 3.6GHz with 4GHz turbo, while the 4790K is 4GHz with 4.4GHz turbo. Hence why the 5K iMac uses a 4790K.