Intel's 8-series chipsets, designed for Haswell-based processors, are seeing defects in their USB 3.0 feature, and although Intel has distributed fixed chipsets to motherboard and notebook players in... New Intel 8-series chipset products in September
The z77 offered some really nice additions to the z68, the z87 offers what, power saving features? no thanks, gonna stick with Ivy and throw some uber fast ram in, like i've been sayin for the longest time lol. Even Ivy-e is gonna be uber coupled with super fast ram, which'll push it over 10% improvement on sandy-e imo. But sure if you're coming from an older setup haswell is fine for sure.
This may go a long way in explaining why the second generation are holding their price so well, and becoming even more expensive on some websites like amazon and Novatech.
I've not had decent reliable USB 3 yet since X58 and about 10 different mobo's across 5 different vendors. The worst one yet - VIA VL800 - on a Gigabyte X79S-UP5 - I've had to disable which looses the 4 ports at the back - random BSOD's whenever it's enabled (and not just when it's in use.)