Wish I had spent more time there.
Shanghai is an exciting city, but I went during Spring Festival, so it seemed like a lot of people had gone home. Nevertheless, I was able to spend a good night out at Perry's a mixed Chinese-expat bar that had decent music, very friendly people, and ok beers. Sight-seeing was excellent, museums world-class, and it is superbly easy to get around.
Insider Tip:Don't go during spring festival. Do some research beforehand to find good spots to go out at night if you want to party. Otherwise, you can wing it and just go where ever, there's always something to see in every corner.