I bought both during the corona lock down here in Germany to support my local dealer. The original plan was to buy them in August but now they could use it more, I guess.
The lens is much heavier than the Sigma 150-600C but the quality is something else. And the focusing! Oh my god the focusing. Even with the 1.4 teleconverter! It is amazing and works so well on the a7III.
The following shots are all made around 840mm, handheld with a very bright sun during noon time.