Another thing to keep in mind is that the 670 your looking at is of reference design by the looks of it. The 7950's your looking at has custom coolers which means lower temps, lower noise, higher potential for overclock. Those 7950's you listed have very good coolers on them. If you plan on overclocking, I would go with the 7950's, if not, the 670's are better out of the box.
+1 i didn't notice what 670 it was till now i thought it was GIGABYTE GV-N670OC-2GD GeForce GTX 670 sorry OP
in that case i don't know which is better but i am willing to bet money the Asus is hehehe