Well, i am not local but I spent my best four years in Hangzhou, I have just graduated from Zhejiang University.
I'd say it's not a metropolis like the nearest modern city-Shanghai and this city isn't filled with rich contemporary Chinese history, either, like Nanjing.(it was the capital of six ancient Dynasties though...)
But I would say Hangzhou is a city where you can find different charm all the time as time goes by and feel the humanism within it. I don't want to talk about West Lake or other famous beautiful places of interest. What attracts me most is that,there are millions of unknown places (with amazing behind stories) around West Lake that you can explore a lot on weekends by yourself,actually. (well, if you really interested, you can ask me specific spots further and you can come to my uni too! : ) ) Also, what differentiates itself from other cities is drivers' manner in this city. In Hangzhou, all vehicles must give way to pedestrians. It's way beyond 'rule' and consciousness, it has become a part of 'Hangzhou style', which is not common in any other cities in China. This is recognized by many other visitors from other cities, too.
The least thing, well..like...traffic jam and air pollution(occasionally) ? you have to be very patient and you'd better take subway as possible as you can, at least it's much better than that in Beijing or Shanghai. : /
-A