I have owned this lens for several years. I've used it on two different APS-C sensor cameras and now the a99 II. This lens is sharp and focuses quickly. It's easy to control when in hand. When used on a clipped sensor, it simply extends the range. It has an SSM motor in the lens. The main downside to this lens is that the motor drains the battery quickly when the camera is in autofocus mode. I even dropped it on a muddy trail recently - no harm. It's well built.