430 is an Double action air-brush this mean you must control air and paint flow at same time (its really requires some dexerity and experience), however A470 is an Hybrid Airbrush which you can use as an double action and single action , this mean A470 = A430 + A320 ,
i am using A470 Contempo and its really good airbrush youn can start as an single action but in future u can use an Double action as well.