The focusing, in general, is good on the camera but the more you zoom into the image you are trying to capture, the more undefined and imprecise the subject becomes

I also have a Tamron 70-300 USD, and while I love the image quality from it, the focusing is noticeably slower.

Still, it's very sharp and has excellent and very quiet auto focus.

Very sharp focus, even at minimum focus distance and max zoom.

The focus is amazing

I noticed right away that the STM and IS on this lens worked wonders of NO sound while focusing and it is very quick to refocus on anything

I also have a Tamron 70-300 USD, and while I love the image quality from it, the focusing is noticeably slower.

The focusing is very fast, it matches up nicely with my 80d.

I think this lens is best used in manual mode as you have more control on the lighting conditions and it can gain better focus