depends on if youll be using wifi, and if you are then is the difference in price worth it?
IMO its a tough decision, but ultimately comes down to if you really need the wifi capability. i do like Asus and trust them more, but gigabyte makes good boards as well. also the gigabyte only has 1 PCIe 3.0 slot, and since you said youre planning on 2 GPUs you might want to go with the Asus.
all in all both are great boards.