We got on each morning, walked our legs off until about 7pm (when all of the museums close) and then took the train back.
We were so tired, the kids (and my wife and I) just wanted to sit in the hot tub and go to bed. And then we would get up and do it all over again the next day. We were there for 5 days and it was non-stop the whole time.
Probably one of our favorite family trips!