To a significant extent, this is an expanded version of this manifesto: wiki.rechtaufstadt.net/index.php/Manifest_Not_In_Our_Name,_Marke_Hamburg!
I think the discussion/interview in chapter 6 was useful; beyond that I got some Hamburg history out of it.
In terms of the main subject matter (gentrification), I got a lot less out of it than I had hoped. I think it serves as a nice introduction with a specific, detailed example, but I don't think it's argumentatively solid enough to convince people.
Finally, for a work claiming to take an activist perspective, there is frustratingly little political commentary or praxis in it.
All that being said, if you're looking for a fairly short overview, this might be the book for you.