I just visited Shanghai recently.....heard so much about it prior to my visit, that i was really looking forward to it. Indeed, it was a great city, very vibrant and cosmopolitan......and when i sat at the starbucks there, watching the world (or rather shanghai) go by, i really didn't feel like in China. It's definitley a city that i will go back again, i think it can be a good place just to chill...... despite some negatives about it!
And here's just 3 things i don't like about Shanghai city :
(a) the food is oily and salty! (yipes! the vegetables are swimming in oil!)
(b) it's crowded! (everyone's in shanghai in oct?)
(c) service staff can be rude! (so be prepared)
Oh, and my brother will be based near there from next year.....so the more reason i will visit ;) wunderful!