I must say that, as a yearly traveler to Germany for the past 20 years, I certainly enjoy and greatly use the German rail system/s. In USA I reside in NJ, which, with NJ Transit, is one of the USA's best transit (Sbahn) systems, and the NEC. So I feel certainly well qualified to make comparisons.
The German U/S/R and IC systems, as built and run, make for a superior rail commute. All are efficient, exceptional on-time records, frequent and fast. My home in Germany is Norderstedt, a near-in suburb of Hamburg. When travelling to/from there, it is quite easy to take the U bahn ( or U/S combination) from a stop 4 blocks from my home to the Hauptbahnhof in Hamburg. The U bahns and S bahns are convenient, clean, and fast.
I never worry about 'extra time' or 'padding' in my schedule/s, since a 5 min 'dwell' time in Hamburg is more than sufficient for catching the Intercity trains to wherever. For a tourist, using the DB Railpass, it's a huge bargain, and includes free passage on the KD Rhine Line boats, which is a 'must do'. And, instead of a $200-300 hotel, for about $40 US you can book a liegewagen (couchette) for overnight travel...and from one end of Germany to other, take a train overnight ...see the sights ...and return overnight to origin, allowing a full day (8am-10pm) for sightseeing. (also way to go to neighboring countries for same types of trips...Paris, Amsterdam, Innsbruck, Vienna, Zurich, Prague, Copenhagen...etc. an easy overnight trip with full day sightseeing and then return) The German ICE high speed trains are terrific...smooth riding, (no bounce and sway , actually can have a full-to-the-brim cup of coffee and not spill it) While not as fast as the TGV...still a lot faster than the best an Acela can do on a good day and a helluva lot more comfortable ride.
For those a bit more inhibited, the extra cost of a double schlafwagen (sleeper) is still reasonable, and a bit more comfortable.
And for those on unlimited budgets, the deluxe sleepers with full facilities, are exceptional.
The Bord Restaurant or Bord Bistro's are a bit expensive, so many residents or tourist travelers will tend to bring their own food on board....or ...grab something last minute at an "Imbiss" (snack bar) at the train station (bahnhof) or even on the platform. The Imbiss food is excellent. (try a frikadellen mit ein bier) delicious!!!! And during Weihnachtsfest (Christmas season) make sure to grab a Glühwein.!!!
Bring back the Slumbercoaches!!