Coming from the 1950s and 60s kitchy Superman/Jimmy Olson/Lois Lane stories, I was expecting more ridiculousness that bordered on idiocy, but there was a lot of stuff to enjoy.
All the stories in this book were from 1943, apparently the height of anti-Japanese sentiment during WWII, so there are lots of Japanese slurs, and all the Japanese characters are caricatures who draw out their Ss like snakes.
Like Superman and Clark Kent, Wonder Woman has a civilian alter ego who works with the superhero's closest companions, and who has to make some quick and careful switches to preserve her secret identify. Unlike Clark Kent, though, Diana Prince is often seen as part of the action/investigation, albeit in a behind-the-scenes way. Diana is also in the army? As a nurse-secretary? Or something similar--"Lieutenant Prince." While she seems to act mostly as a secretary, it's still very interesting, not to mention nice, to see a woman, well, not Lois Lane-ified.
A secondary character, along of the lines of Superman's Jimmy Olson, is Etta Candy. Only unlike Jimmy, Etta is actually useful and has a brain. And while she's sometimes played for laughs, I was pretty shocked--Etta is short, fat, and seems to eat nothing but sugar, but is a trusted friend, is often enlisted (or volunteers) to put herself in danger to catch a bad guy/foil a plot, and is a self-confident, awesome character. Heck, in some of the "In The Future" stories, she's a professor, possibly of something science-y.
(Comics, what happened?)
The stories themselves were fun, because, although sometimes basic, they at least have action and enemies who actually kill people ad intend to hurt rather than the same guys who hold up Superman with handguns and never get anything done ever. single. time.
(If I'm referencing Superman too much, it's because his stories are so very prevalent when finding older major-superhero stories. Also, I haven't read anyone else.)