I was pulled into the "Superman vs Hollywood" book mainly through the introduction by Mark Miller, where he stated the book had many new stories.
I did find some of the stories compelling, but overall, I'd heard lots of them over time, so the book wasn't quite what I had hoped for.
It is nice to get a longer term perspective on DC Comics and the history of their most influential character. Some of the behind-the-scenes information is good - like Bud Collyer, the voice of the radio series choosing to remain anonymous to avoid being tied to the Superman character, and this feeding into DC's marketing of Superman as "real" and not voiced by an actor.
The history of Siegel and Shuster (the creators; writer and artist respectively of Action Comics #1) and their shabby treatment by DC over time is always a fresh horror. To be fair, DC did "settle" numerous times, each relatively reasonable (except for the need to go to, or threaten legal action), but they never really provided a sum commensurate with the $$$ the character brought into the comic, radio, TV, animation, Broadway and movie franchise. Having Siegel and Shuster die relatively poor (particularly Shuster) and relatively unrecognized as the Superman "fathers" is just sad.
The background stories around the Superman movies (Christopher Reeve series) are educational as well. The playoff between directors and producers, and the entire new realm of creating a modern blockbuster on a comic hero was not as obvious as it now seems. Late changes to the project planning moved the ending of the second movie (the "back in time" solution to Lois' death in Superman 1) to the first movie left a hole in the second movie that was "filled' oddly - Superman throwing cellophane crests at his fellow Kryptonians, and seemingly killing them all when they were depowered (Lois helped kill Ursula too) - all in good fun.
The cessation of the franchise after the Superman 3 (with Richard Pryor) and Superman 4 (nuclear disarmament) was a good one, as the series seemed to be running downhill pretty fast. The various scripts and plans between Superman 4 in 1987 and "The Man of Steel" in 2013 has some fascinating aspects (Superman vs a giant spider??? Nic Cage as Superman??? ).
If the stories are new to you, the book is a good read. I did find myself running through the book fairly quickly, but I didn't find as much "new stuff" as I'd hoped. All in all, a pretty good read.