My best acquisition

Simply amazing. It is heavy. Even very heavy for its size, but we do not doubt the quality of manufacture when yours in hand.
As for picture quality, I have simply no objective that rivals it.
Mounted on a Canon 6D, fast and accurate autofocus. I did not use the sigma as this dock was not worth the trouble, but I think it is possible to further improve all that.
And for the rest, it's just perfect.