I have the Tenth Anniversary Edition (1998), all 1551 pages. Don't know much about the latest version, but the 1998 copy made interesting reading, even though it was a steep learning curve.
"Is it worth the money". Considering the 10th edition book is 3" thick, over 9" long, over 7" wide with 1551 pages, then I would say it is good value compared to other publications of lesser content for similar money. I would imagine that the latest version still contains some of the articles from previous editions with modern updates.