Just got back from a trip of just over a week to Speyer (Germany) and Nancy (France).
The big thing to note is that Deutsche Bahn really is frankly crap now. Over half the journeys I took were severely delayed due to missed connections, and whenever I was in a large station there were serious delays all over the departure/arrival boards.
First day I took the train from London to Brussels and then Cologne, for an overnight stay. I stayed at the Ibis Cologne am Dom, which is literally inside the station building. This meant that I noticed that the train I took from Brussels to Cologne, which was a Paris-Dortmund Thalys, after arriving in Cologne about ten minutes late, sat in Cologne Hbf for about forty minutes for what was scheduled as a 10 minute stop.
Took the RE from Cologne to Mainz, and then connected to Speyer. The trip down the Rhine was very scenic but surprisingly crowded, probably because it was a Friday and the weather was very nice. We got into Mainz about half an hour late because of delays at various stations due to the number of people trying to get on and off, and then people leaning on the doors so that they didn't register as properly closed - a couple of stations before Mainz the driver absolutely lost it and started raging over the PA about how people needed to get away from the doors.
At Speyer I stayed at the Goldener Engel on the edge of the Altstadt, on the railway station side. It was generally very good, apart from the mattress of my bed being basically just a block of foam rubber instead of having springs. If I'd stayed more than four nights I think it might really have upset my back. Also I had dinner in the hotel courtyard one evening (first time having Saumagen) and got bitten all over by a swarm of midges, the lumps didn't go down for four days.
In Speyer I went to the transport museums there and at Sinsheim near Heidelburg, plus the railway museum at Neustadt an der Weinstrasse. Won't go into nerdy detail but very much worthwhile. Apart from having to hang around Mannheim Hbf for an hour on the way to Sinsheim, because the S-Bahn from Speyer to Mannheim was delayed.
I also want to recommend a very nice Italian restaurant in Speyer, the Picco Bello in Korngasse where I had an excellent linguine with wild mushrooms.
Then came the most ridiculous episode of my trip, booking the train ticket from Speyer to Nancy. The DB website wouldn't let me purchase the ticket, so I went to the Travel Centre in Speyer station. The issue turned out to be that I was booking a ticket for SNCF from Strasbourg to Nancy from outside France, which meant that I needed to give the person at the travel centre my name, home address, email, phone, and date of birth, and even then it seemed like she had to go through dozens of clicks on her computer to do it. When I turned round to go, having bought the ticket, there were six people queued up behind me.
Speyer to Nancy was pretty trouble-free, fortunately, and I checked in at the Hotel de Guise in Nancy where I'd stayed before. It had had a bit of a refit since then, and I got a room on the ground floor in the inner courtyard. Unfortunately, the wi-fi was rubbish. I can see the problems, since it's a sixteenth-century building with thick stone walls, but they needed more repeaters/boosters. Other than that, though, it was lovely and comfortable.
In Nancy I revisited the Museum of the School of Nancy, and for the first time the Villa Majorelle, which is now open to the public. The Museum is highly recommended, but the Villa had less to see than I expected and I would only recommend it for serious fans.
Also highly recommended in Nancy is A la Table du Bon Roy Stanislaus, a restaurant in the centre which serves 18th-century style Franco-Polish food, in memory of Stanislaus Leszczynski, who was Duke of Lorraine under Louis XV, who married his daughter.
Then a trip home via Paris, with 30 minutes delay on Eurostar.