I have traveled due to Business in the last six month a lot using the train (in average one trip every ten working days) and I commute to work using train (and bus).

I have been on time only once (!), the most (70%) had a delay than less than five minutes (what did not count as delay), but the worse things, the other 29% had a huge delay of more than 15 minutes. My personal record is 95 minutes due a train with a engine damage between as far as I remember Bonn and Cologne.

Several trains got canceled on my several trips (but I was able to take another one).

I usually plan to take an earlier train for travel to Frankfurt Airport to be on the safe side or even travel the day before, depending on the departure time.

But the delay had sometimes something positive - I was able to get the sometimes faster while direct previous train due to its delay