M on the bund is a classy place, the weather has been good recently, hope you were able to get a decent table on the terrace. I'm a fan of their weekend brunch myself, and their pavlova (am i spelling that right?) is reallllllyy good. Then afterward go down a floor to the bar. Creative and god cocktails. (god i'm trying not to make this sound like an advert for them lol)
For dim-sum, and chinese food in general, I'd recommend crystal jade, over in xintiandi. Maybe its my fondness of it from my experience at the takashimaya location on orchard road, but either way its a great chinese food experience.
You are right, I've noticed I eat better here in China than I do in the USA, extremly spoiled by the choice and quality of cuisine here.