Yeah that is helpful thanks Justin, you have to turn up the volume on the Pro one to match the level from the Air, but it does sound better to my ear, the Air sounds tinnier. I still don't know if the Pro has the same "studio quality" 3-mic array that is used in the 16-inch Mac's book Pro.
It might take somebody doing a studio singing test,
like this studio demo video with the 16". With all the reverb and processing, this sounds good enough for home demos. If that's the case with the M1 Pro, then it's worth the $300 alone, for me.
Also, since video-conferencing (zoom etc) is likely to continue to have a big place even post-pandemic, mic quality is increasingly important there too.