just my personal tastests. i am working on Live, where apc benefits from smarter implementation to an application. you have got bit more sort of organized control on the things + full 8 chanel mixing surface. Ohm has only 4 full-control channels. 8x8 grid of buttons which is pretty nice, but i am missing faders right beneath em. controller looks pretty and is deffinitely worth thinking about, if you're not working in Abelton Live.
indeed Ohm benefits of USB powering,which is good.