The V20 Companion is ... a companion book to the V20 core book.
It has its shortcomings, but it also has some interesting content that could be quite useful, depending on the ST, the game, and your own purposes.
Looking for details on Titles and Boons for the Cam, Sabbat, Anarchs and more? Congrats! half of the content of the book is just for you.
Looking for a page spread and info for the Caitiff? It's right there.
Looking for how Kindred utilize today's technology? ... YouTube, Social Networks, and the likes? There's (arguably the best update to the V:tM setting) a nice chapter for you.
How about some setting locations all around the world? A bunch of pages with about 4 paragraphs for each, describing places of importance/interest to Kindred.
Included in the page count (aside from pages of contributors, cover page, legal info, and artwork) is an Appendix that includes some un-used/un-finished material that shows some of the ideas that were unfinished, or deemed unworthy of the V20 Companion, but still presented in their most raw forms nonetheless.
In all, if any of these things sound like they would complete your understanding/interest in V20, then this book might be for you. But if none of this sounds specifically important to you, then you might be disappointed.
Because of its limited usability, its somewhat awkward content, but because it does also contain information missing from the V20 core book, I would say that this book does have its audience. Whether or not it's for you?...
NOTE: this book contains illustrations with nudity.