This is a great book, but it's important to note that it doesn't include the ENTIRE Dark Phoenix saga. It includes Uncanny X-Men issues #132-140, while the Dark Phoenix saga begins in issue #129. The first three "prelude" issues of the story arc, including the introductions of Kitty Pryde, Emma Frost and the Hellfire Club are introduced in Volume 4. If you want to read the entire Dark Phoenix saga in one book, then you should probably purchase the Dark Phoenix compilation.
Nevertheless, this is still a really nice volume, particularly if you are a completist like myself who prefers to read all the comics rather than just selected arcs. Some of the earlier issues in Volume 4, even before the ones in the Dark Phoenix books, include some important set-up points to the story. After first reading the Dark Phoenix as a stand-alone book, I re-read it in Volumes 4 and 5 and definitely preferred reading the complete lead-up.
Besides the final six issues of the Dark Phoenix story, Volume 5 includes four quite different subsequent issues. The series caught its breath a bit with the "Elegy" issue (summing up the history of the X-Men), followed by a cracking stand-alone annual centered around Nightcrawler, and then a 2-issue story arc with Wolverine in Canada retangling with Wendigo. These last stories are quite good in their own right - containing good back-story on Kurt and Logan - but of course tend to get somewhat lost, squeezed between the iconic Dark Phoenix and Days of Future Past arcs.
Unfortunately, this volume ends just prior to the 2-issue Days of Future Past story line, which is available in its own title volume, spanning issues #138-143 and the annual.
In addition to an introduction by Chris Claremont (written in 2004), Volume 5 has several excellent extras, all related to the Dark Phoenix saga:
- Phoenix The Untold Story #1 from 1984. This includes a reprint of most of the artwork from #137 (with some changes to the dialogue - I found myself flipping back and forth to note the changes) and a different ending. It also includes "The Dark Phoenix Tapes", a transcript of a roundtable among the creative team and editors, discussing the story.
- The "Phoenix" chapter of Bizarre Adventures #27 from 1981.
- All the covers of Dark Phoenix trade paperbacks published since 1984