This book, despite it being written in the 1800s, is impressive simply because of its scope. In my career as a costumer I have never seen another costume history book that offers a wider range of detailed and beautifully rendered images of costumes from around the world.
If you want to use this as a visual reference the only thing you have to keep in mind is that it ends in 1800 (i.e. if you're looking for the Civil War or Victorian era, you're out of luck).
My only major complaint relates to the text that accompany the images. This is a two-volume set, the first and largest volume contains all the plates, and the slimmer volume contains the descriptions that match each plate (in three languages!). These descriptions are not at all adequate to give the relevant information about all of the costumes in a given plate. For example, a page may have fifteen numbered images of different African tribesmen, but the description will only list nine, and give no indication of which is which, ignoring the number system of the plates entirely. You can generally get a good ballpark on the dates for a plate, but there's nothing for individual pieces within that plate.
Upon further research I learned that this edition is, while longer than its predecessor, still a much pared down version from them original (at least for the text, I believe all of the plates are still there). This is not what upsets me, as I understand the need to edit down what would otherwise be 1000 pages of text that would make this set twice as massive as it already is. But they could have been MUCH better about what they edited down.
For example, take a page that has 30 pieces of Celtic jewelry on it, numbered accordingly. The description would be something along the lines of "Celtic jewelry: torques, necklaces, brooches, penannular brooches, belt buckles, cloak fasteners..." etc, etc, whereas I would MUCH rather have it read "Celtic jewelry: 1. Brooch, 3rd century, Gaul. 2: torque, 2nd century, London". I do understand the need to edit down, but the anthropologist and historian in me would rather have an extra 100-200 pages and objective, useful data than the catch-all descriptions they do have. Now I feel like I need to keep an eye out for an original copy so I can have access to the full descriptions.
Now that my rant is done, however...
Would I recommend this book as a resource? Yes.
Do I think this is a good visual reference? ABSOLUTELY. The breadth of this book's content is unmatched,especially for regions like Africa that normally don't get a lot of coverage even in non-European costume books. There are even plates that are devoted to jewelry, or furniture, or the interior decorating of the period/locale (ranging from Baroque boudoirs to Mongolian tents)that further help the reader get a sense of the period and historical context. And it is a good starting point for research. The physical book is also beautifully put together.
All in all I give it four stars.