As you are having already a six core i am not sure.
But it may be that in some areas the FX to be better.
Strangely enough(in spite of the negative hype over FX) the power consumption might be lower with the FX.
You also have more instructions on the FX pipeline for the future applications.
It may also be cooler.
I intend to buy one myself and replace the 975BE that i use,but choosing a motherboard after the 970A-UD3 disappointment it s very hard for me personally.
In your place i would go for a FX 8320.
LE:We seem to have similar video cards ,but mine unlocked by using a simple slider to 6970 no need to flash