I can't say that US chocolate smells/tastes particularly like vomit to me (a USan), but I do note that UK chocolate to me has a certain vaguely artificial-fat hint to it, like a sweet industrial solvent like percoethylene or something.

I'm sure this is far more to do with "the way in which your chocolate tastes different and what it reminds me of" rather than anything actually bad in either of them

I'm told there are plenty of people in UK who enjoy US chocolate, but they're probably gammon.