Hellfire13 :
8086k is just a better binned 8700k with higher clocks. It has .3ghz bump over 8700k for an additional $50 approx.
That's only for single core turbo, which rarely occurs in the wild. All other turbo levels are identical to the 8700K. Basically, you're paying $50 to get an extra 0.1 GHz of OC headroom (on average). And even that still has an element of luck, and may not even come into play unless you're doing hardcore overclocking (i.e. delidding).