Hate to break it to you, but most of the "Cadbury" brand chocolate sold in the US is actually manufactured by Hershey. At least, on the back of them is "manufacture and packaged by the Hershey company" or something to that effect. On my last trip to England just to test whether the Cadbury bars I can find here are the same, I bought a dairy milk bar in Hethrow and brought it back. I then bought the same exact (wrapper) product here. Tasting them "blind" I could tell which was which pretty accurately.
Also I happen to like American chocolate
, it's largely a matter of taste what constitutes "high-quality" chocolate. Of course there is the cheap and nasty stuff they make christmas candies and such out of, but by and large the chocolate here is good stuff.