You are right, it seems it is as best as it has ever been... I'm now running it in full speed (overclocked at 1.500MHz).
I had some issue regarding Sound when opted for Jack or Auto instead of HDMI...
I realized that, when playing on Dreamcast emulator, the audio does not work if I choose for jack or Auto instead of HDMI. And for this emulator the sound is always too higher than the others (when considering HDMI sound).
Maybe it is a known issue from the old version (5.18), by the way, I just realized it now.
Another thing is that, now, once my RPI3 B+ is set to update automatically, I'm receiving a message to update to version 5.18 (but I'm with 5.19 intalled)... I know that it is becouse it is a different version than we have in the server... so I just turn the automatic update off to keep 5.19 intalled and not downgrade it to 5.18...
Let me know if would you like to me to do some specific test in order to help you to turn Batocera even better!