This talk of stability is interesting. My hunch is that those of you with stability issues on your overclocked i7 machines it’s coming down to too aggressive overclocking, dodgy settings or dodgy hardware. I have had something like 6 or more overclocked high-end i7 machines over the years, all built by myself but I bought a pre-overclocked mobo/cpu/ram bundle from OCUK - they know what they’re doing and the overclocks have been 100% rock-solid stable during 24/7 rendering. Literally zero BSOD or stability issues. My current 3930k workstation is overclocked to 4ghz with 32GB RAM and renders happily for days on end with zero issues.
I think you have to rule out stability from the equation because if it’s done right, an i7 is just as reliable as a xeon rig, but costs far less for a similar performance. That money saving means you can spend more on additional machines for a network, resulting in greater net power, or more money on other components like screens and cards and storage etc.
But this is just my experience.
my experience is the same. if you choose good parts and don’t go crazy with the overclocking then stability isn’t an issue. i generally stick with asus motherboards as they are really good at doing regular bios updates for the enthusiast boards.