I looked at that, but:
* AMD no ECC, nor a similar chip with it. Intel has a Xeon E3 which is basically core as the 6700 with ECC enabled. Doesn't hurt that it's cheaper as well.
* AMD had 70% of the throughput, but much less on anything single threaded. So many normal UI apps like say web browsing are slower.
* the AMD solution runs hotter, so you need to either tolerate more noise or pay more for case/fans/power supplies
* My use case includes running 24/7 so burning extra watts (and running the AC to cool them) adds up.
After considering it all I went with the E3-1230v5. Near 6700k multicore performance, near 6700k single thread performance, max 80 watt TDP, and idles much lower. I also get a M.2 slot which allows pretty amazing performance (well above SATA) and a tiny footprint (gum stick or so).
I don't buy systems often though, the machine it's replacing is a quad core 3.0 GHz machines (Q6600) with 8GB ram from 2007. So I don't mind spending a bit more if it's going to last. Hopefully with 32GB ram this new machine will last quite a while.