I bought it so I'll throw in my 2 pesos. Please do not consider this a full review as I bought it in the airport (kindle version on the maxiPad) to have something to skim while I flew to DefCon. I definitely did not do a full, detailed examination.
Book vs. the free stuff: Approximately the first half follows very closely to the free materials. It seems to go just a little bit deeper, or in a slightly different direction, here and there but nothing major. It wouldn't be anything you couldn't put together with popular free material plus a few forum searches. However, it seems like the second half of the book goes more in depth into the materials around expanding the framework, SET, rolling your own stuff, some pen test methodology, etc.
Is it worth it?: That's completely up to you. To me it was worth every dime because I expensed it to my lab budget. Joking aside, I'm glad I have it as it is a handy little reference guide that I can carry with me. Plus, I feel that the authors (rel1k, muts, et al) have already given so much to the community that I have no heartburn what so ever with them making a few dimes off of my purchase. If I was on a tight (or no) budget I'd probably take a pass on this, but when I'm in the position that I need an orderly, portable into to the material when I'm training up a new staff member this book would be on the top of the list.
CISSP, CISM, CISA, GCIH, GREM, CEH, HMFIC, KTHXBIROFLCOPTER