I used it every time it happened, very rarely when I just slept in. My boss also came by S-Bahn so he was late from time to time as well. Of course if we had an important meeting or a customer appointment we came in a whole hour early, to compensate for 3 train failures, which never happened. But if you came 20 minutes late on a regular Tuesday nobody cared that much (boring office IT job).
I used it every time it happened, very rarely when I just slept in. My boss also came by S-Bahn so he was late from time to time as well. Of course if we had an important meeting or a customer appointment we came in a whole hour early, to compensate for 3 train failures, which never happened. But if you came 20 minutes late on a regular Tuesday nobody cared that much (boring office IT job).