>>1791647German S-Bahn systems are probably better than 80% of commuter systems around the world, that said, it's just really rare to find really convenient commuter trains that aren't just shuffling around all the poor people who can't afford a car.
My main takeaways from German S-Bahn would be:
>often separated lines from mainline trains>always (or almost) electrified>operates more as a larger subway system with frequent stops, high frequency and few or no skip-stop services>German rail infrastructure is notoriously underfunded, so it's all got a vibe of neglectPersonally, I'm more partial to the Swiss S-Bahn concept, which uses shared mainlines (if necessary 3 or 4-tracked), larger double-deck trains, lower frequency (15 min tops, many lines 30 minutes especially further out from the city), stops further apart and skip-stop services on some lines.