It's pretty cool, you just set a mate and they synch up, no messing with rates up and down or worrying about the slave following trim or mixing inputs. It even re-labels it in the menus as L-AIL and R-AIL instead of AIL and AUX1 or whatever. Same with the elevators, it says R-ELE and L-ELE
You also dont have to worry about some slider yanking the "flaps" down by mistake
(seen that one) because the flap mix part of flapperon mixing wasnt 0'd out.