If you wish to travel smoothly in Germany, like flying but hate the hassle, try Lufthansa’s Rail&Fly service. It is a combination of a flight ticket and a train ticket, operating from and to several cities in Germany. A round trip from Helsinki to Stuttgart via Frankfurt cost me 238€ last April. The trip consisted of a flight from Helsinki to Frankfurt, a smooth baggage claim at the Airtrain terminal (follow the train station signs before the airport arrivals baggage claim and Airtrain signs after that), a short walk to the train track platform and a fast train ride to Stuttgart. Here is more information about the service.
In theory, this should have happened vice versa, as well, but (no surprise) as Lufthansa staff decided to go on a strike, the easy ride ended up being a combination of three flights via Vienna and Stockholm to Helsinki hours later than the original ETA.