If you're going to buy an edition of the 9/11 Commission Report, this is probably the one you should get.
Here's why. You can download the whole report for free, in PDF format, from either the GPO or the website of the 9/11 Commission. That means you can read the whole thing on your computer without spending one red cent.
The 'official', and more expensive, editions of the book don't include any text you don't get in the PDF version. This New York Times edition does; it opens with nearly seventy pages of articles from the Grey Lady (none, I think, written by Jayson Blair) about the formation and activities of the Commission.
This edition doesn't include the endnotes, but it does include the superscripts that lead to the notes so that you can check them in the PDF files if you want to. If you're like me, when you sit down to read the report, you don't particularly want to flip back and look at the notes anyway; that's for later, if there's a point for which you want to check a source. And precisely because this edition doesn't include all those additional pages, it's easier to tote around for lunchtime reading.
Of course, since the report itself isn't protected by copyright in the U.S. (it's a government work), you can pretty much do what you want with the free electronic version -- including printing it out. But the paper for that job will probably cost you more than the price of this edition, and the result won't be very handy to lug around with you.
As for the report itself, well, I'm not going to review the content here. Just read it and make up your own mind; that's what we do here in America.