This is a great drive for the SkyView Pro mount. I recently purchased this from opt when it was on sale with free shipping. If you do a good polar alignment with this motor you will be tracking objects really well. I did a polar alignment and then powered up the true track system. It was everything I had hoped for! I was able to track objects at 200x without having them shift out of the field. I could observe without having to constantly use the fine adjustment knobs to track. The ring nebula and the double double in Lyra were great to see for such a long period of time. The reason why a half a star is deducted is really because they redesigned the D.A. motor and it does not go on quite the same as the instructions say. The design was very much an improvement! They moved the port from being a flimsy add on to the top of the motor to being in the motor drum on the side. Much more durable, but the instructions should have reflected this change. It took a bit of finesse to get it to fit just right when mounting. Very much a worthwhile investment - if you have a skyview pro mount and want to track without spending the bucks on a goto system, this is for you!