Wyvernoodle: I took day trains Amsterdam - Berlin 4 times (return), a night train once (also both ways) and a flight once (also both ways).
Advantage of the day train is you see a bit more, get to walk around, there's a cafe compartment, and you arrive in the middle of the city. But usually quite late in the day.
Advantage of flying is less travel time and more convenient arrival time. But you still need to take transport into town. I don't remember which airport I flew into (may have been Tegel) but it was another 45 minutes into town. And personally I hate security checks but not everyone has a problem with that.
Berlin is one of my favourite cities in the world, especially the areas Friedrichshain, Kreuzberg, Prenzlauer Berg, Mitte.
Cecile - thanks for your note. I agree about the train and the factors you put forth are indeed those I have thought about. Will try the flight this time and maybe the train next time. I have a feeling that Berlin, like Amsterdam, will speak to me strongly and that I will return.
Yes, Berlin oozes history and has a lot to offer. The only thing is, do not expect Berlin to be a pretty city with one city center. Every area sort of has its own center. And it's a city of contrasts: parts so ugly that they become beautiful, old monuments, hyper modern shopping centers, good museums, funky shops, old fashioned beer gardens, lots of street art, everyone ignores the no-smoking in bars rules but everyone obeys traffic rules because fines are hefty. And of course if you pay attention you can notice a difference between the former West Berlin and East Berlin.
At the same time it is widespread, but very doable by bike. Using subways, you will walk a lot... (Some of the connections are a kilometer walk it seems. And you'll walk a lot between points of interest). But they are highly efficient, frequent and punctual. I prefer to bike, you see more too.
P.S. A link I saved for next time I go... About the best open air locations (city beaches, terraces etc). It's in Dutch but the pictures and names should tell you enough. And below the last recommendation you will also find a Facebook page in English for Berlin Open Air. enjoy-berlin.nl/de-6-beste-open-air-locaties…
Back to #8: correction as I just studied the timetable more in depth. There is one direct train per day taking 7 hours. For the other six trains there _is_ a transfer but it's short and in Hannover. Sorry...
All the best,
<Erik> & [Sandya]