What makes a good technical book 'good'?

This question came up StackOverflow.

For me, the following ingredients make a good technical book great -

1. Written mostly in plain-English
2. No-fluff, straight-forward tone & a conversational style
3. Author identifies the needs of audience in the beginning & meets the expectations set
4. Has some kind of takeaways you can benefit from like crisp summaries, checklists, practical examples, re-usable code samples.
5. Content is well-organized & structured.
6. Attention is paid to technical accuracy, grammar, layout & fonts used
7. Illustrations, backgrounders & infoboxes are provided where required & important information is highlighted.
8. The author is an expert on the topic and isn't under the "curse of knowledge". A person contributing to the technical community (via online forums, meetups, source code donations, blog articles) would be more hands-on & therefore be a better teacher.