I have the lens for a few days and get to decide if I want to keep it or not.....
First impression is that the build is much nicer than version 1, it just feels better. Unfortunately, I got my hands on it late in the afternoon, an hour before sunset, with heavy rain clouds moving in so I just got a few quick snaps before the rain hit and I had to leave....
The minimum focus distance is shorter than the version 1, so here is the first picture from the lens, a Junco, 600mm, F8, about 3 1/2 meters away, and a way too slow 1/60 of a second exposure, ISO1250, on a 7D II. Very poor conditions, but it turned out OK.... First is cropped to about 2/3 of the image, the second is a 1-1 crop, both with no processing. There is a bit of motion blur on the bird's head.... about a dozen shots were taken of the bird and all the others showed motion blur worse than this one....