It works very well----but, I mean, not too fast movements...I shoot with a tripod and often have to wait until the desired animal comes in front of the lens in Africa.

Hello,
I used it to take pictures of planes at airshows. It's good because it's not too heavy. The Pro version is much too heavy when hand-held.
The sharpness is very good for a zoom of this type.
As far as focusing is concerned, this should work on a Canon. When using a Sony with an adapter ring, autofocus wasn't always easy.