This is Claremont's X-Men at their height, post-Byrne '82-'84, with the first big Brood story, plus Carol Danvers / Binary, the Starjammers, then Rogue, then Madeleine Pryor, then a wedding that doesn't happen, then a wedding that does happen, then Morlocks, then ...
You can begin to see the signs of decay in the quality of the book, though. The in-jokes and too-cute-for-words indulgences, the focus on Kitty Pryde as teenage reader proxy (said focus including, alas, Lockheed the Dragon -- played far too often for cutesy yocks). And if you think about it -- how many of the key elements of the period (space whales, Storm's death, Madeleine, the Morlocks, Lockheed, Amanda Sefton) still have impact on the present-day stories? (Granted, we're talking about going on thirty years ago, which is one of the problems with the comic world, but still ...)
On the other hand, there's some triffic stuff here. For one, sandwiched between Dave Cockrum and John Romita, Jr., we have Paul Smith's fantastic artwork, which covers some of the best stories in the volume, particularly the Wolverine/Mariko wedding adventure in Japan, and Madeleine Pryor as Dark Phoenix.
The book also contains a reprint of "God Loves, Man Kills," one of the first Marvel written-for-purpose graphic novels, and the (vague) inspiration for the second X-Men movie. It remains a an incredible work, hurt here only by the inexpensive black and white printing of Brent Anderson'spainted graphic novel.
This is an "essential" for fans of "early" X-Men, Chris Claremont, Paul Smith, and Wolverine.