Here in California, when you tell an acquaintance that they're particularly clever or sweet, they grin pinkly and do a little riff on, "aw shucks, stop it again, quit it some more," and like you the better for it. In New England, they're liable to lift their chins -- apparently avoiding a slobbery little dog -- and take it as their due ... while wondering what your agenda is, and bracing to resist it.
I know this because, after living in each place for a few years and watching the expressions and asking why, I found myself doing these exact same things. (I'm not immune, but I try to be aware.)
I'm also planning to go between the mid-Atlantic seaboard and the Northeast, which I've done before, and that has a charming set of subtle cultural potholes of its own.
For instance, if you call a stranger "ma'am" or "sir" in Alexandria, they figure you have nice manners and relax a little.
If you do that in New York, they raise their chins (ever so slightly) and figure you've taken a lower peg than themselves in the pecking order; then they're either magnanimous or obstructive, but usually magnanimous.
If you do that in Massachusetts, they look around in a flustered manner and can't quite figure out if you're making fun of them or are putting them on a pedestal they aren't sure they should occupy. ... Which is in interesting contrast to the reaction to compliments.
Mind you, those who know me well have it figured out: compliments are taken pleasantly and "ma'am/sir" lightens the mood. So I'm not worried.
But I am glad that California has the cultural weight that it does, because -- as I learned long ago -- saying in an explanatory tone, "I'm from California," smooths out any number of cultural faux pas. And there are sooo many pas to faux up.