Pages 6 to 71 are the full text of the novel. It's well laid out and nicely illustrated. I'm not sure if I'd like to read it in this format (either on screen or printed) but it's handy having the main text included in the sourcebook.
The rest of the PDF is forty pages of actual game content, parts of which are very good. But first the bad part: I bought this on the strength of the D20 content, unfortunately the only D20 content are stats for the main characters in the novel, and a racial package for Martians. No weapon or vehicle stats, no "crunchy bits". What there is appears to have been bolted on at the last minute in order to get that d20 logo on the cover. Very, very disappointing.
So chucking out all the Action! system crunchy bits, what's left? There's a very sketchy two-page setting chapter on Edwardian England. The Action! crunchy bits chapters have some good descriptions of the various weapons and vehicles, as well as some nice illustrations. There are NPC stats for all the major characters in the novel, dual statted for Action and D20. Then there's chapter 5 - ten pages of GM advice and ideas for running a War Of The Worlds game, including changing the period, alternate endings and possible sequels. This section is superb, and almost worth the cost of the PDF alone. There then follows one page of unit stats for using the Monster Island game to fight out the war... nice but..
In summary, if I'd been an Action! system GM wanting to run a War Of The Worlds game, I'd rate this a 5. If I'd bought it just for the background and descriptions, knowing the game material was for a game I didn't play, then I'd give it at least a 4, as it's well written and attractively set out. But I bought this to do the game in D20 which the blurb claims this book will let you do, but there just isn't enough D20 content to allow that. So this gets a 3 purely for Chapter 5.