Having driveb my 2020 for 2000 miles (1000 slowly like a granny and the last 500 like a maniac) I can attest that the sound is completely neutered. Valves open sounds more deep and gentle grumble, but not how AMG is supposed to be. IMHO, compared to Audi and BMW, the AMG has been heavier and more of a brash muscle car. Now the exhaust note is barely a step above daily commuter. I added the ASR to keep valves open all the time and it is better, and on the racetrack my kids say it is loud, but no comparison to my W204 with secondaries removed.
I am going in for catted DP in a few weeks just for sound, so no retune to minimize warranty issues.