I also use my camera mostly for shooting images of my children, and they are always in action...almost, except when sleeping
But, maybe K-01 could keep with them, it seems that it locks focus pretty quickly, that is what I need. Tracking is a SF for me and my K10D
Ok, one theoretical question: Does contrast AF depends on the quality of the sensor and its dynamic range? I think it should. Also, if you pair it with good lens that lets a lot of good light to detect fine contrast, maybe K-01 could surprise with its AF capabilities.