I'm Impressed by Vinge's pinyin

I didn't enjoy it that much, but one thing that impressed me about Vernor Vinge's Rainbows End was that when one of the characters spoke Chinese, it was rendered in Chinese (pinyin) correctly, by which I mean the grammar was correct and idiomatic, and the pinyin was rendered with tone marks, which is rare even in academic writing. (Even if he didn't do it himself, he knew enough to consult someone who knew to use pinyin correctly.)