I'm looking to upgrade either my GPU (R9 270X) or my CPU (i5-4690k). I only have the budget for one or the other right now (about $300). Would a GTX 1060 6GB or i5-7600k be a bigger upgrade? I know that WOW is more CPU reliant I'm just unsure which would be the bigger upgrade. CPU is not currently overclocked. Any advice or opinions are appreciated.