One is single slot with Dirt3 the other is two slots and no free game.
The asus has a slight overclock:
xfx core: 800 Asus: 820
Memory xfx: 1125 Asus: 1150
So really you gotta answer do you want the free game(xfx)? Do you want a single slot solution(xfx)? Or do you want the "fastesr" of the two (asus)?