Personal preference really, however I don't like it when bass drowns everything else out. If you're not using trueplay also, then it is a must. Borrow an apple device and set it up, only reason why I still have an old Ipad is to use it for that haha. But I use the below settings, as find I can crank the volume up 1/3 of the volume bar at night, or half way in the day, where as if I leave everything default anything above a tiny amount on the volume slider and it's too loud for the room. I also prefer everything else sounding super crisp, like glass shattering etc and with these settings due to being able to use higher volume, it works better for me. Also the difference between compressed and uncompressed is actually quite big I've found on the Sonos arc. If your TV supports Earc, then again highly recommend testing films in Dolby Atmos (trueHD). I usually use the opening scene from 'Baby Driver' as my go to test when changing settings, as it has a bit of everything.
Bass -4
Treble -6
Sub volume -5
Surround audio tv level +1