ICE trains rule. They’re comfortable, clean and fast, and you just hop right on without having to go through an hour-long bureaucratic nightmare at the airport.
I’ve driven in fast cars on the Autobahn between the same cities as I took ICE, and I’ve never come close to the ICE’s time. That includes the ICE stopping a few times for passengers (they don’t stop at every little station, just the big ones).
That's because you didn't drive fast enough.