Some things I've noticed that might be useful for people to know.
Buying a rail pass in advance saves money. I paid 310 euros for 5 separate days of unlimited F travel. By contrast if I'd arrived at Köln station to buy an F ticket for the next departure to Frankfurt last Sunday, it would have cost me 127 euros just for the 1 hour, one way journey.
The bistro on board a DB train charges approx double what you would spend if you bought food or drinks at one of the numerous stalls that are in all except the smallest suburban stations. I would expect to pay 1-1.5 euros for a cup of tea on the platform but it's 3.20 on board.
There's no large luggage racks on most ICE trains, only the overhead racks. The place for larger bags is in the middle of the F carriage where the seats face opposite directions. Between the backs of the 2 rows of opposite-facing seats there is space to stow larger bags.
As to luggage, unlike the ease of a Swiss train where you just roll your bag on as the carriage level and platform level are the same, on a DB train you'll have to lift your bag onboard. It might be about 20cm or it might be higher, depending on the kind of train. If it's an Italian train it'll seem about a metre
.
Unless you're very determined and organised, forget about using public transport like bus or underground to get to the train station if you have luggage. Like in Paris you will encounter endless stairs. Some stations have lifts or escalators, but not at every entrance and not always working. Again the Swiss do this so much better than the Germans.
Just like there can be gate changes with air travel, there can be platform changes with DB trains and they may not be announced clearly in English. I was waiting for a train from Frankfurt to Berlin. First there was an announcement of a 15 minute delay. Then right on the scheduled departure time there was an announcement of a platform change, which caused a headlong stampede of pax and bags as everyone thought there was no delay any more and panicked about getting to the new platform in time. I did not hear either announcement in English. Luckily I can remember enough university German to understand what was going on. (Bet I can't write an essay in German about German literary romanticism any more though
).
There can be compensation for some sorts of tickets if the train is late and you miss a connection. Again they don't announce that in English. My train left Frankfurt late but made up the time en route and arrived in Berlin on schedule.
If you reserve a seat at the DB service centre you can ask for a seat facing the direction of travel but it doesn't always work. At Frankfurt for example, the trains enter in one direction but leave 'backwards' so what's facing the direction of travel into Frankfurt will become the reverse on the continued journey.
Don't trust the DB service centre for accurate info about when the next train is. They seem to have cut-off times, and if there is a train in the next 5-10 mins you could still catch it but they don't tell you about it, probably because their computer isn't showing it. Check the departure boards instead.
There's not always good views from a train. There's lots of tunnels, cuttings and hedges/trees/screening around the tracks that can stop you seeing very much at all. Like cloud cover on a flight I guess.
Moving on the high speed trains is surprisingly difficult. It's much harder to keep your balance than on a suburban train, a plane or even on a ship in a gale. If you have balance or mobility problems I'd recommend sitting still until the train stops.
Many trains are going to the popular destination Nichteinsteigen or its near neighbour Bittenichteinsteigen. Don't get on these
.
If there's a spare seat on the platform that is both clean and in the shade, it's going to be right next to the Raucherbereich (smoking area)
.
And to end on a sweet note, DB hand out little heart-shaped shortbread biscuits in F