snowdog on 15 July 2011
They're both as accurate as each other. I own both.
The difference between the two is that Move is the only one that can provide an Automated Reality experience a, currently, MotionPlus is the only one that self calibrates via Ai Live's LiveMove 2 middleware. Move requires you to manually recalibrate each time you experience drift, and it also drifts more often - particularly when you shake the Move controller.
