I know that chipset wise, the 790GX is better than 790X- powerwise and pci wise. that's the only difference i can see. i use a similar dd2 board and I say go for ASUS, i dont know about gigabyte but usually if you mess up the asus board will eventually boot up with default values and you dont have to pull off a reset cmos. they overclock very nicely too. make sure you get some nice ram for them and a hyper 212+ for your cpu, it drops your temps very nicely and the thermal paste that they ship with it is 10x better than arctic silver or any other leading brand.