PcMag reviewed the A9III and concluded:

The camera is tuned for speed, both in terms of performance and capture rate, with 120fps Raw drive and an autofocus system that’s a little more advanced than that from Canon or Nikon. That said, picture quality lags behind contemporaries, and you pay a premium for the cutting-edge tech. High-level sports and action photographers understand that nabbing a moment perfectly is more important than some grain in an image, so nothing quite matches the a9 III on the market for those needs. But if you don’t mind a slightly slower capture rate or intend to roll a lot of video, the Editors’ Choice-winning Canon EOS R3 and Nikon Z 8 are both top-notch alternatives.

Preorders (shipment start Feb 21):
Sony A9III at BHphoto . Amazon . Adorama . FotoErhardt . Fotokoch . Calumet . WexUK .
Sony 300mm at BHphoto . Amazon . Adorama . FotoErhardt . Fotokoch . Calumet . WexUK .
Sonny A9III Vertical Grip at BHphoto . Amazon . Adorama . FotoErhardt . Fotokoch . Calumet . WexUK .