I just received my copy of Michel's Zeppelin- und Flugpost-Spezial 2017/2018 (Zeppelin and Airmail Specialized Catalog), and I thought I'd share a mini-review.
This is the 3rd Edition of this catalog, and the first revision in 15 years. It's comes in at 582 pages.
The book itself is in Michel's standard format -- hardcover, about #8776;150x230mm (#8776;6x9"), with a couple bookmark ribbons.

Table of contents:

The first half of the book covers the Zeppelin Post. It lists the flights of German and American zeppelins, and includes a handy Michel-to-Sieger catalog number conversion chart.

The second half of the book covers German airmail.
The first section lists the Pionierflugpost, or airmail carried on "Pioneer" flights from 1909-1914.

Next, the catalog contains a section listing all the semi-official airmails. This section is essentially the same as that found in Michel's Germany Specialized catalog.
Next, the catalog lists all first flights within Germany.

Next, the catalog contains a list of airmail stamps. This section is basically the Germany Specialized catalog with all non-airmails removed. It includes not only Germany, but all related areas which would normally be found in Michel's Germany Specialized (Danzig, Memel, WWII Occupations, Feldpost, etc.).
Next, the catalog lists all postal stationery and private postal stationery with airmail postage or designs. As with the airmail stamp section, this is basically a condensed version of Michel's postal stationery catalogs.

Finally, the catalog has a series of sections containing airmail cancels:
Airfield cancels --

Airline cancels --

Military airbase cancels --

Airmail postmarks --

Luftwaffe postmarks --

Airmail confirmation marks --

Other confirmation marks --

Interrupted and cancelled flight markings --

Commemorative and Promotional Cancels --

Overall, I'm very pleased with the book. I had not previously owned Michel's German language Zeppelin catalog, and I'm impressed with its thoroughness. I do own the English language version of Michel's previous Zeppelin Post catalog, and the zeppelin portion of this catalog appears to be a much more thorough, updated listing (not to mention including hundreds of pages of airmail listings which were not in the English language Zeppelin catalog).