Where to cut/add for our 24 full days trip ?

5 nights seems like too much for the Rhine and Moselle. Trier is nice, but I think if you've already seen a bunch of other similar sized cities in Germany, it kind of loses it's sparkle.

If you're basing yourself in Nürnberg, consider combining Coburg on a long daytrip to Bamberg. Coburg has a nice Altstadt, but the star attraction is Veste Coburg, the large castle that overlooks the town. For my money, this is the best castle experience in Germany. I would give it preference over the far-too-touristed Rothenburg odT.

I'm in the minority opinion, but Salzburg didn't blow me away. It's nice, no doubt, but the Altstadt is really small and a lot less colorful than many others in Bavarian and Austria.

If the purpose of your visit to Garmisch is to make the Zugspitze ascent, then a daytrip is reasonable. Don't try to plan this far in advanced, pay attention to the short-term weather forecast and jump on the first day that offers clear conditions. If it's just to see the town... I wouldn't bother. Don't get me wrong, I love the place, but I love it most because it provides easy access to all sorts of amazing Alpine adventures.

Quedlinburg is amazing, but I wouldn't see it as a daytrip from somewhere else. The nearby towns of Goslar and Wernigerode are worth a visit, as is the ascent up Brocken, the highest mountain in the Harz, either by foot or Eisenbahn. Erfurt is worth a look, but skippable if you can't find the time.

A few quick kid-friendly suggestions: If you want to take a break in the middle of your vacation while letting the kids run wild, consider one of these indoor waterparks/thermal resorts: Tropical Islands near Berlin, Kristall Palm Beach near Nürnberg, or the grandest of all, Therme Erding near the Munich airport. Leipzig, which you would likely pass between Dresden and Nürnberg, has one of the best zoos I've seen anywhere. You mentioned Playmobil Park, but depending on the route you take between Munich and the Mittelrhein, you may pass near Legoland Ulm.

Hi,

If you take time out of the Middle Rhine area and add a day to Berlin to make it 6 nights, you would have time to do a day trip to Leipzig only a little more than one hour away. At the Military History Museum in Dresden-Neustadt you'll see prior to the WW2 and Bundeswehr history the exhibits and history of the Saxon Army, which prior to 1914 had a military attache in Berlin.

To pursue the history, if you want to see more military history, you might want to see what in Prussian-German historiography is called the Battle of the Nations Museum, the Völkerschlachtmuseum, which in anglophone historiography is referred as the Battle of Leipzig (same as in French). When I was there last in 2011, evidence of refurbishing and restoring equipment could still be seen, since the huge monument had to be made ready for the bicentennial in 2013. A short day trip from Berlin will do it, take the S-Bahn outside of Leipzig Hbf to reach the Völkerschlacht Denkmal (monument). I am sure this momentous event is covered in Mil Hist. Museum also, all the more so since the Saxons were part of it.

For now our trip is:
Berlin: 5 nights
Dresden: 3 nights
Nuremberg: 3 nights (day trip to Bamberg or Wurzburg and Rothenburg)
Salzburg: 3 nights
Munich: 4 night
Cochem (or another base): 5 nights
Luxembourg: 1 night

What do you think about that ?

There are all kinds of wooden toy and Christmas ornament factories South of Dresden. a fun Alpine slide near Coburg. Rothenburg ob d tauber has a fun wall the kids love to climb, and a dungeon and torture museum!
With kids you need to keep the museums down and try to add zoos or tierparks. They are great!! There is a fabulous national park outside Berlin where the kids can see animals and climb around. If you have any open air museums near you, they are so fun for kids. There is one near Coburg.
Make sure you plan everything around your kids. You will have to go back alone or when they are older to see all the churches and museums. Kids do like castles, but they can get boring to kids, also!!

Salzburg has some alpine slides and don't miss going down into one of the salt mines, the kids will love that!

In Bavaria my kids loved the partnach gorge!! Check out all these things on line, sounds like a wonderful trip!!!

Thanks for thoses ideas !

Of course we will allow plenty of time for our kids, but we also look to have some time/choice for us but you are right about thinking about the kids !

I'm curious to know more about that national park near Berlin, can you tell me the name ?

Coburg wasn't on our list but it sure look lovely. We have 4 nights in Nuremberg there's gonna be tough choices to make !