I own a GA-Z77MX-D3H running i5 3570k @ 4.2Ghz, 2 x GTX 670 video cards, 16Gb 1600Mhz memory and the system has been stable and consistent to use for the almost the year that I've owned it.
i also own an ASRock Z77 Extreme4 motherboard, which actually cost me less, has better cooling, offers better voltage control for oc'ing and has been absolutely stable and a joy to use.
Also USB 2.0 and 3.0 seems to work a hell of a lot faster on my ASRock Z77 Extreme4, my GA-Z77MX-D3H USB 3.0 just seems slow in comparison most the time.
If I was on a tight budget, wanted support for Sli, wanted reasonable voltage control for oc'ing, then my choice if I had to make it again would be the ASRock Z77 Extreme4 motherboard over anything Gigabyte has to offer for the same price.
Different story if I was buying an upper end motherboard like the GA-Z77X-UP7, if I had the money for such a luxury I'd definitely prefer that over many other manufacturers motherboards in that price range.