I think it's great. It will be in the list of books to read next for sure, especially since it's free.
FWIW, the background is that it has been under a Creative Commons license since 2004, it has had about half a million downloads/readers (guesstimate, of course), is used as a text book for introductory programming courses in at least 8 universities worldwide, and has been translated to at least 5-6 languages by volunteers.
I'm building a list of free books for people to move onto after they finish mine. I'll put yours in the list.