I think all of the major manufacturers make decent boards these days. ASUS, MSI, Gigabyte etc have been designing and manufacturing motherboards for a while now. They know that reliability is a big factor in gaining brand loyalty. You will always get the odd failure here and there. And when you consider how complex a motherboard is, it's suprising that there aren't more failures !
Hope you get your board sorted, and don't be put off by Gigabyte. If their boards were unreliable, we'd know about it. I'm not a Gigabyte shareholder, by the way, I sometimes use MSI boards, and they also seem reliable.
My brother in law has the same system as me including the GB board and has no issues. Mine has just been a nightmare.