I actually haven't noticed any lack of precision on Kinect. But, then, I don't play games with it -- just use it for the Your Shape series of workouts (and, I've been through *everything*: P90X, Insanity, Spartacus, etc. -- and *nothing* keeps you as honest as Your Shape). I also use the new Nike workout on Kinect, however, not as good as Your Shape.I have to say, I have at home kinect and ps move. Kinect is great for kids but the lack of precision annoys me. PS move its way more precise for games like boxing and golf. It's a shame it looks stupid with those colored balls.
I have to claim ignorance on the PS3. But, from what I've seen, those glowing balls would be a deal killer for me. Having to either hold, or strap something on, would just detract too much from the experience, after the scanning technology of Kinect.