I think if people step into this book thinking they will find an example of realism, I think they will be disappointed. Although the issues of racism, segregation, Jim Crow laws, and their effects on society as a whole are very real, Ellison approached it with a wry wit. I wouldn't quite call his approach tongue-in-cheek, but it definitely wasn't on the level.
In a sense, the book had a spirit like that of Homer's The Odyssey
. The protagonist was blown of course as if by the gods and found himself on a quest to find his way home. But his journey is not as heroic as that of Odysseus, although it appears to be at times. But nothing is ever as it appears to be for an invisible man.
The only downside to this book is probably only a factor of reading it more than 50 years after it was published. The passages were long. The point could become buried in a lot of superfluous language. Granted, that may have been common to the writing of the time. They would probably laugh at our 2-page chapters in modern genre fiction.