Oh it is
In my opinion it is a masterpiece, way ahead of anything Aeronaut Books has published so far!
I have something like 1000+ books on American aviation and it easily takes the top position of all of them. I believe you have Peter Grosz book about Austro-Hungarian aircraft?
This is the US equivalent and if someone gave me the awful choice of choosing which one is best, I think I would give the honors to Casari.....
Come on Clint, buy it....you only live once....
Cheers
Stig