Hi, Well, the motor is just one component of the entire chain (AF sensor / microcontroller / motor / coupling mechanism / lens mechanics). I've got a 601 among other bodies, and its AF is really noisy and slow. It sounds to me like some electric chainsaw. IMHO the main reason for its lack of speed is its lack of computing power. Therefore a more powerful motor would likely lead to increased battery consumption (and the 601's batteries are expensive). I even have the impression that the AF logic is sometimes (mainly in low light situations) unable to determine in which direction it should start focusing and has to find out by trial and error. Nevertheless, it's a great body, and I don't understand why Nikon didn't integrate its cool flash functionality (EV comp., rear sync etc.) into all other bodies released later. Cheers Boris boris dot achermann at switzerland dot org
