SLI mod= dunno if it can still work (check anandtech), but you can make the board support 2 gfx cards (the SLI board of this costs a lot more)
japanese capacitors=those small things on the mobo that look lik tiny battery, the dfi has high quality capacitors, which supports better OC (dunno how this works, but if you OC on a cheap board, you can bust the capacitors)
it's well designed for OCing because(one of the reasons) is that it's designed by oskar wu (he designed really good OCing board [he used to work for abit])