I have had a riot with this lens. AFMA on my 5diii is -2 wide and +1 tele. In other words pretty much right on out if the box. If you want to see pics. Goto to my flickr oage and look at pretty much any of the bird pics.
Make a reasonable offer and it is yours.
I know there is a 2nd gen coming out and understand the price is a bit depressed.