> With a native speaker you could shred through those books fairly quickly.

I'm not sure this applies equally to Chinese, as it's not a phonetic language. Extensive speaking/listening practice isn't totally transferrable to reading tasks. There are many things I can hear for which I might not recognise the characters (because I seldom see them written) and, equally, there are characters for which I know the meaning (because I read them when shopping online, and have seen them in context a lot) but not the sound.