I've been dealing with a lot of people recently, asking for builds but not feeling comfortable with overclocking, its quite reasonable, and when they're already looking at a build in the 2500k/3570k range then you might as well get the unlocked version to make sure its future proofed when the price difference is minimal or even nothing.
With regards to the OP's question, for general gaming you won't notice a huge boost, but for live streaming you'll see a huge difference, all be it you'll probably still be stuck streaming 25-30 fps due to the lack of cores versus an i7