Another Muenchener here, and I second ensiferum's take - Sbahn is significantly worse than Ubahn, in all measures. ie, if you want to go to the airport, you always schedule an extra hour, just in case you get dumped out in Ismaning or Unterschleissheim (with the confidently delivered excuse "dieser zug faehrt nicht weiter") and need to uber / wait for the next overly full train (whose signage may or may not be correct).
On top of that, unexplained, sudden, irrational waiting time extensions until finally 'zug faellt aus'.. really? if the train doesn't exist, just tell us so we can make other plans now and not in 30 mins. Besides, the posters communicating all of the recent schedule changes due to work are horribly complicated, written in long essay form when all they really need to say is what stops are out of service when (how non-german speakers navigate this nonsense is beyond the imagination). On top of that, the MVG's recent absurdist claim that all schedule changes will be conveniently available per MVG app :DDDD riiiiight... if you read the thirty page long yellow text!