Dikötter is widely criticized by historians and sociologists. He's only praised in mainstream lay press by people who don't know anything about this topic. He wrote for that lay audience, not academic, because it is easier to launder his bias and dishonesty to an audience with no familiarity on this topic, which is why I said to become informed before reading him in order to avoud miseducation.
You can feel free to read those histories and criticisms, as you should always do before accepting or recommending a pop history book.