I think just 1 or 2 days is all you need in Venice. It looks great and you can't take a bad picture. It's a great place to come with someone special, eat good food for a night and take some good pictures. As far as I can tell and found from locals, there is no large partying. I spent 4 days and that was way too long. Even great pizza and pasta can get old fast. There is nothing to eat but pizza and pasta. I found the exhibits a little boring, it's just kind of nice to take a walk around.