This book is a bit of an odd beast. It's set in between the first and second trilogies in the Sentinels series and is comprised of a couple of shorts from the creator (Van Allen Plexico), a bunch of short stories by other authors set in the Sentinels Universe, an essay on the origin and development of the series and an Official Handbook of sorts to the various characters. As with any anthology, there are stories that work better than others. I can honestly say that there are no absolute stinkers in the bunch, though there are certainly stories that didn't really click with me for whatever reason. There is also art sprinkled throughout the book and the vast majority of it features Pulsar (which is fine with me, as she's my favorite character in the Sentinels universe). The piece on page 41 by Gary Bedell is my favorite and I wish he'd contributed more than just that one image. My favorite stores in the book were: "Best Laid Plans" by Wayne Skiver, "The Camping Trip" by Ron Fortier, "The Road to Hell" by Bobby Nash and "The Adventures of Captain Cook" by David Wright. That last one is a really odd piece but I found myself quite interested in the "behind the scenes" storyline dealing with the Captain Cook series. As for Van's two 'official' contributions, the second one was a lot of fun but the first one didn't really impress me. There were some cute moments but it kind of felt like a "fill-in" or "inventory" story. I think I get what Van was going for -- something lighter than the usual Sentinels fare but I thought some of the humorous moments missed the mark. "Future Shocked" was a major improvement, however. Actually, what I enjoyed more than anything was "The Making of the Sentinels" which summarizes how Van came up with the core concepts and developed them. I've always enjoyed those kinds of things and this piece was more than a little inspiring.
In summary, is this an essential piece of the Sentinels saga? Eh, I don't know. It is fun, though and if you're a fan of the Sentinels Universe, I'd recommend it. I would NOT recommend that anyone start their journey into the Sentinels universe with this book, however. Start with the original trilogy and if you enjoy that, try Alternate Visions.