This is a very readable style guide until the last chapter.
Pinker has done an excellent job of creating a readable persuasive style guide to the English language. He argues against some out-dated writing advice. I think this will be the reference to judge style guides against.
However, I found the final chapter to be confusing. This contrasted strongly with the preceding chapters. I could have been overwhelmed by the quantity and advice given. Whatever the reason, I lost my way and came away disappointed.
This is well written, clear, and makes good sense. It is also interesting to read the author's thoughts as he interprets a variety of prose. I'm just not sure we needed another grammar book; not enough here is fresh.