So, AJ, this is 11 days Central/Eastern Europe (3 countries) and 2 weeks Western Europe (3 countries), even though your headline topic is Central Europe. And you seem to also have time in Italy for a wedding plus time in Greece before the wedding,
From your other posts, looks like 37 days total. So, 5 weeks and 8 countries. April and May. You’ll beat the heat, at least. But slow down, whatever you do.
My initial reaction to this post was
(1) skip Hamburg - where I have never been, but you just want one day to see one sight and it sticks out like a sore thumb unless that sight is super important to you.
(2) see Paris, rather than the river cruise. But again what’s important to you? But I’d spend most of the week in Paris with a single day trip elsewhere at most (and not to Versailles).
After looking at your other posts to see the bigger picture, I think you should figure out a couple of themes or interests that hold your trip together. Maybe it’s the ancient world - Greece and Italy - and then a transition through Italy and the Renaissance to Western Europe. Maybe it’s Greece and Italy followed by Eastern and Central Europe (with time along the Adriatic, including Venice, perhaps Ravenna, and Croatia) without piling on Western Europe in addition. Maybe it’s beaches, followed by mountains. Your interests. Your trip.
What’s important to you? What’s pulling you in one direction or another for the post-wedding part of your trip? Once you figure that part out, spend some time with guidebooks. Not just RS, but also Lonely Planet and DK Eyewitness. Some of RS shows.
We spent 18 days for just three Central Europe countries in 2018: Prague (4 nights), Vienna (4 nights) and Croatia (11 nights). Since then, we’ve had two 30 day trips, one country each (France; Italy) and just to portions of those two countries. (Bordeaux, Dordogne, Loire, then towards and to Paris; Southern Italy - no further north than Naples).
See more. Experience more. Travel less