Not enough of a performance increase to justify the cost.
I agree, I would not go with the 4690k. There wont be much of a performance boost form your 4460. The 4790k will give you your best boost, but it wont be a miracle either. Only on games that can use the SMT. So like BF1, you would see a big performance boost with a 4790k. But other games that are not as CPU heave, the difference will be negligible.