Had a '19 C63S for a few years, nice car, was my DD sucked in the winter, so I got rid of it. Build quality was good, no rattles, AMG does a nice job with tuning in sport mode + exhaust gets snotty. If it wasn't for the brakes no one would know what I was driving. Yes, interior was nice, not as nice as my Audi S5 but close enough.
The 5BW is an entirely different story. I got rid of my GT500 as I wanted something that would fly under the radar and be as much fun as the Shelby. Mission accomplished! I didn't buy the blackwing to look at the interior, just needed something that was comfortable, I bought it to bang fucking gears, and yet cruise into a board meeting, "under cover." For me, the BW exhibits sounds only found from a SC V8, similar to the GT500 but better. Yes, the cabin is a bit muted, however just crack the rear windows down while cruising around town and you will be all smiles! The BW handling is in another stratosphere compared with the C63S which felt "wobbly" during triple digits in Mexico of course.
Moral to the story- the BW interior gets it done, nice and comfortable, plenty of room. It's the rest of the car that will absolutely put fucking smiles on your face all day every day, no exceptions. And if you're like me, spinning the tires into triple digits when you're in the mood = priceless!
Good luck bud!