Overclocking mITX boards

PCP gives a list of Z87/97 mITX boards, and it's pretty short. How much of a difference is there between the most expensive (Maximus Impact) and the cheaper boards? They range from $120 to $170, to the $210 of the Impact. I can't seem to find any documentation on how exactly mobo overclocking power differentiates across brand. Also, is there any real difference in Z87 and Z97 for overclocking?

The K series CPUs are pretty easy to overclock these days. I would think that in most cases you'd be limited more by thermals than by the motherboard, especially in the smaller ITX cases. There may or may not be a difference otherwise, but IMO it isn't that much.

It used to make a a bigger difference, back when overclocking meant that you pushed your motherboard bus speeds way out of spec. That's not how overclocking works these days with Intel's mainstream desktop platform.

Regarding chipsets, go Z97. Word out is that future Broadwell chips may be supported by them, plus why wouldn't you go with the latest/greatest?

Desktop Broadwell LGA is Socket 1150