In a respectable showing, but perhaps disappointing to some, Bill Claff over at PhotonsToPhotos.net shows that the new flagship A1 camera only has dynamic range roughly as good as the A7r Mark IV and the A9 Mark II. For most ISO settings it sits in a very narrow range right between those two cameras.
In what is sure to inspire much online forum gnashing, the same data sets show that the A1 comes up slightly short of the Canon R5. It performs similarly versus the Canon 1DX Mark III, which itself performs slightly worse than the R5.
With some exceptions, the differences are slight. A notable exception is at ISO 400, where the R5 appears to have two stops of dynamic range advantage over the new A1. This may be the only setting where images would be noticeably affected.
[UPDATE 1/2/22: Nikon’s Z9 data can now be found among the dynamic range data set. It shows performance just shy of the Canon R3 and the Sony A1.]
PhotonsToPhotos.net is a long-standing web resource for reliable third party dynamic range testing.