My reason for a Xeon is simple - the E5-2686V3 performs better/same as 8core i7 in 3d rendering, for a price of 6 core i7. I don't need to overclock it, so I can use a silent Noctua cooler, and overall hope to get a semi-silent system.
I'm also looking to try a few gpu renderers, so pciex lanes...