really enjoying mine!
i'm still in the process of setting all the custom buttons though.. recently shot 2 music videos with it,,
have to figure out the best profiles , i know with the a7s2 i was on slog2 but there was a bit of customization i did as well so that the files.
just ordered a cage for it, i want to start using my atamos with it more so i can record directly to prores 422 rather than transcoding.
the a7s3 is everything i was hoping for .. now why did i sell all my lenses..lol
10bit 4:2:0 XAVC HS is the answer. No need to transcode anything, assuming you have a video card that supports it.
for in cam, SLOG3 is the best, then SLOG2, then HLG3.... I've settled for HLG3 because screen grabs to heif to iphone is pretty darn nice SOOC. For photos, I do raw + heif because it's simple to export to iphone, and using pp1, I can tweak SOOC heif to get it to look near the HLG3 screen grabs, for some reason, HLG3 photos do NOT work the same, which is unfortunate. It's an incredible camera, love having the hold and toggle buttons in a video centric camera, I can control all things manual really fast, shutter, aperture, iso, and kelvin, I've been run and gun fully manual since 
a shame no shutter angle and a way to toggle framerate....







