Hi,
I'm with Jolphil on this and I am running an 8 Series Motherboard which is excellent.
With regard to core unlocking yes, there is a problem but it is not confined to the series 8 motherboards and I have tested a few Gigabyte boards for core unlocking and they have all failed. I have also passed my results onto Gigabyte and I know they are looking into the problems being encountered. As with all things it can take time to resolve such issues and they are not always solved in the manner in which we would like. But, be assured it is being looked into.
My own views on Core Unlocking probably won't sit comfortably with many but it is not a given right. You cannot buy a lower spec'd processor and expect it to be unlocked successfully despite what you might feel. Gigabyte's advertising might not be the best with regard to this is it sells the motherboards with ease of unlocking as a selling point. This is where they have gone wrong, not in the motherboards that they produce. Something that you should also bear in mind is, that possibly, Gigabyte have set a higher standard for the CPU unlocking feature than other manufacturer's. There have been many successful core unlock's on Gigabyte 7 & 8 Series motherboards so they must be doing something right.