Honestly, Goodwin's scripts are just functional--not exactly rich with subtext. I guess that's perversely suitable given that the strip was originally written by the conscientiously flat and flinty Dashiell Hammett. The writing is not at the level Goodwin would later achieve with Batman and Manhunter.
The reason to buy this is that Corrigan is one of the best drawn adventure strips of all time--one that starts out virtuosic and gets slowly better. Williamson was immersed in the classic pen technique going back to the late 1800s. His ability to summon rich and varied tones from a field of close-set pen marks is essentially a lost skill today, when the nib pen is mainly used for outlines and scattered textural marks. (Nibs are generally avoided by younger artists, who cleave to inexpressive but predictable Microns.)
In terms of composition, design and execution, this is beautiful, almost flawless, work. Williamson's strong reliance on photo reference works out well for Corrigan (who by this time is entirely modeled on Williamson himself) and other male characters, less well on the female characters. (Williamson, for all his many gifts, didn't have the ability to tweak the attractiveness of his models in a Gil Elvgren way; he was more beholden to the facts as shown in the photos he shot. It's a shame that a draftsman of his caliber didn't feel comfortable working off the cuff more.)
Highly recommended if you care even a little about art and inking. Williamson's mastery of the brush was equal to his command of the pen, by the way.