Why? As discussed theres arguments that 1156 is better than 1366, 1366 has full SLI/xfire but as most users stick to one high end gfx card this is moot, 1366 also has triple channel RAM over dual channel, but again very few users will notice any difference. 1156 on the other hand has better turbo boost, on board PCI-E controller resulting in better gaming results both at stock and when clocked, check out anandtech and techreport, where youll see for gaming the 750 outperforms the 920 AND the 950, so the 860 will spank it
Tech Report which shows initial comparisons of 750 vs 1366 at stock speeds, as above it beats both 920 and 950
Anandtechs comparison of chips clocked at 3.8