As an SR-2 owner, I'd think about this board only once Intel releases the ivy-bridge E series of CPU's later next year, as they'll be made at 22nm, use 30% less power because they also use intel's finfet tech( vertically stacked transistors, rather than horizontal), so that for a given overclock given that it uses less power, it's also easier to cool down, as well as the added improvement in performance from the ivy bridge architecture itself, and of course having 8 cores onboard.
The Xeon versions of the current sandy bridge E's, with all 8 cores enabled and still using the 32 nm process, even if they make it to 4+ Ghz on the overclocking front, are going to be using so much power to do so, that it'll become a pain to keep it cool unless you're into high end water cooling...We can forget air cooled with high overclocks, as the current list of models that will be released, already lists the highest end version as dissipating 150 watts TDP at 3.1 Ghz, so you can imagine where that TDP might end up once in the 4+ Ghz region(yikes), hence my preference to wait for the 22nm process.
http://www.cpu-world.com/news_2011/2011102701_Prices_of_Xeon_E5-2600-series_CPUs.html ...Scroll down a bit.
As for the number of memory slots, i couldn't care much for the 12 slots as good DDR 3, using 4 GB modules rated at 2000 Mhz with decent timings already exists, so with 8 slots in total( 4 per CPU), that's already 32 GB of ram onboard, and the best overclocking and overall performance wil be achieved with a single module per memory channel, not 2.....Look no further than EVGA's own X79 classifieds and all of them have only 4 memory slots only and none with 8 slots.....That says plenty right there.