USA/CA Preorders:
Sony 200-600mm FE at Amazon, BHphoto, FocusCamera, BuyDig, Adorama and Henyrs.
Sony 600mm FE GM at Amazon, BHphoto, FocusCamera, BuyDig, Adorama and Henyrs.
EU Preorders:
Sony 200-600mm FE at Amazon DE. Calumet DE. Amazon UK. WexUK. ParkCameras. Amazon FR. Amazon IT. Amazon ES.
Sony 600mm FE GM at Calumet DE.WexUK. ParkCameras.
Asia Preorders:
Sony 200-600mm FE at Sony Japan. Sony Australia.
Sony 600mm FE GM at Sony Japan. Sony Australia.

Colby Brown tested the new 200-600mm G lens and writes:

With the FE 200-600 f/5.6-6.3 lens, Sony has once again continued to close the few remaining gaps in its extensive mirrorless lens lineup. While this lens was not given the G-Master status that is reserved for Sony’s ultimate top tier glass, it is still an incredibly impressive lens that is capable of capturing some truly amazing wildlife images, especially if you have a little bit of light to work with. With a variable aperture of f/5.6-6.3, it certainly isn’t going to be winning any awards for the fastest telephoto lens on the market, which is fine in my book at its price point.

Shooting with the Sony 600 f4, and Sony 35 f1.4 on the Sony a9 by Kenneth Jarecke.

The German reviewer from Opticallimits tested the lens and concludes:

It is easy to spot why the Tamron 28-75mm f/2.8 Di III RXD is so popular. There is, of course, the moderate price tag combined with the fast max. aperture which sets it apart from Sony offerings. Optically it is decent – for such a lens – albeit it comes with a couple of carefully placed compromises. At the wide-end of the zoom range, it is quite sharp across the image frame when stopped down to medium aperture settings whereas the center performance remains superb at 75mm which is where you’d typically use a large aperture setting anyway. Thus the mainstream settings offer quality where usually needed and you will probably agree that most of the provided sample images actually look very decent. That being said, technically there are also obvious weaknesses when using the lens on a high megapixel camera. The corner performance isn’t all that hot at large-aperture settings and for a sharp result across the frame you should stop down to f/8 or f/11. While you can certainly achieve decent object isolation via a shallow depth-of-field, the quality of the bokeh can be quite rough in difficult scenes – when shooting at f/2.8 at least. As far as image distortions, vignetting and CAs are concerned, most users will rely on image auto-correction thus you can live happily ever after. If you look behind the scenes – thus into the unmodified RAW image – you can spot medium distortions at the extreme ends. Lateral CAs are fairly low at the image borders but intensify in the extreme corners. The vignetting is also high at 28mm f/2.8 and 75mm f/2.8 albeit this isn’t unusual in this class.

The build quality is on a very decent consumer-grade level. We are not convinced that the smooth finish will stand the test of time without scratches but out-of-the-box it certainly looks good (albeit a bit long-ish). An annoyance is the tendency of the rubberized zoom ring to function as a dust-magnet in no time. The moisture-resistant desisn is certainly a plus. A highlight is the fast and silent RXD AF motor. Some users will surely also appreciate the close focus capabilities of the lens which is a classic value-add on many Tamron lenses.

If you can’t or don’t want to afford the Sony FE 24-70mm f/2.8 GM but still want an f/2.8 standard zoom lens, the Tamron is a good and light-weight option IF you can live with the rather moderate 28mm setting at the wide-end.

Tamron 28-75mm lens at at Amazon, Bhphoto, FocusCamera and Adorama. in Europe at Amazon DE, Amazon UK and Amazon FR.

Fengniao posted these detailed A7rIV images including a new comparison with the A7rIII:

Sony A7rIV and new accessories:
Sony A7rIV in USA/CA at BHphoto, Adorama, FocusCamera, Amazon, BuyDig, Henrys.
Sony A7rIV in EU at Calumet DE, ParkUK, WexUK, Calumet NL.
Sony A7rIV in Asia at Sony Japan. Sony Australia.
Sony VG-C4EM grip in USA at BHphoto, Adorama, Amazon, FocusCamera, BuyDig, ParkUK, WexUK.
ECM-B1M Digital Audio Shotgun Microphone at BHphoto, Adorama, Amazon, FocusCamera, BuyDig, Park UK.
XLR-K3M Mic at BHphoto, Adorama, Amazon, FocusCamera, BuyDig, Park UK.