If you travel around Germany....you end up using public transportation, and you have to start admiring it. There are problems....one has to admit. But then you look at the complex nature that they've gone to, and the relative low-cost of transportation, and you have to give them a thumbs-up.
First, train travel is exceptionally safe, and for the most part....runs on time. Sure...about every four months....there's some rail accident but if you consider the number of miles of track and the number of trains running every single day....it's pretty safe. As for on-time rates? Well....typically, it's the winter months where you see trains running thirty to sixty minutes behind schedule....especially with heavy snowfall occurring.
Second, as you draw a circle around every major city in Germany.....there's this massive bus operation that is dependable and within the cost range that people demand. I will admit....some towns get served by one bus an hour.....over a ten-hour day, and maybe that's not exactly the best of schedules, but it's better than nothing.
Third, if you stood up in Mainz, and wanted to make a weekend trip to Berlin....it's simple enough to make the reservation over the internet, and even reserve your first-class seats....if you wanted. Hungry? Most of the long-distance trains offer a restaurant on-board, and for a higher-than-normal cost.....you can eat while you move along.
Fourth, for the inner-city areas....the subway and trolley-car operations can be figured out in a matter of minutes by gazing at the city metro map. Trains are numbered and you simply move from train to trolley to bus, and get to your final destination.
Fifth, yes, there are occasional specials for long distance travel. Don't plan on this occurring much....but it'll happen once in a while.
Negative things? When a bus breaks down in the middle of nowhere.....between a city and a town....don't anticipate a "rescue" bus for at least an hour.
No seats on the train available? Well....yeah, this does happen in the summer and you might be standing for an hour while you travel from point A to point B.
Trains don't cool that well in the summer? Well....yeah, if you get up into the 90-degree range, don't anticipate the AC system really doing that well. And if's up over 95-degrees....I'd advise you pause on your trip until after 3PM.
The Bahn-card discount? If you rarely travel long distance.....the Bahn-card may be worthless. It tends to offer ten to thirty percent discounts.....depending on which card you bought. If you intend to travel at least once a month, to a destination that's two to four hours away....then the Bahn-card is worth the money.
The biggest negative that an American can come up with? Well....there are two issues that I tend to see. First, if you are lugging two bags with you....to reach an airport....train travel is lousy. There just isn't a great method of getting on the car, and storing your bags. It's a hassle. If you just have one overnight bag.....then just tote it onboard and slide it under your seat. The second issue involves these once a year strikes that tend to occur with the Bahn folks. If you do return from a vacation spot on a Sunday....to the Frankfurt airport.....you might discover that the Bahn is barely running. You might have to schedule a hotel for the night and wait till the next day before you can return to your home just two hours away by train.