Alex Phan got the new MEGADAP ETZ21 Sony E to Nikon Z Autofocus Adapter sold at Megadap.net. He is using his best GM lenses on the Nikon Z 9 and this is his feedback:

• Full AF on all focus area
• Eye AF works. Super fast.
• Let just say it works almost like native lenses (95%). Still miss AF here and there but that is on Z9.
• It is one of the best adapter to date that be able to drive the linear motor of the 600GM like native Sony Camera.

Test video:

Some images:

Sony 16-35mm at BHphoto. Adorama. Amazon. Calumet DE. FocusCamera. Fotokoch DE. WexUK. Calumet NL.

SonyAlphaBlog concluded:

The PZ 16-35mm F4G is an very good all around 16-35 zoom and excellent in video.
For photos if you go with the Sony FE 16-35 mm F2.8 GM you will gain only in the corners and only at 50-61 Mix
For video production the PZ 16-35 F4 G is more handy on a day to day than the excellent but very bulky Sony FEC 16-35mm T3.1 which is more reserved for static production on tripod

Photographyblog concluded:

Overall, the FE PZ 16-35mm F4 G is a better fit for videographers than photographers, who may not appreciate the slower, looser, unlabeled power zoom control which replaces the traditional mechanical zoom.
On the other hand, it’s precisely that technological development which makes the FE PZ 16-35mm F4 G the smallest ultra-wide-angle zoom lens currently available for Sony Alpha full-frame cameras, so even photographers who only ever shoot stills should seriously consider this lens for its unique blend of portability, features and image quality.