SMAD is an early Block work. In it, the development of his sparse writing style, quick turning plots, and complex alienated protagonist is already well formed. The plot seems a bit far-fetched but he has great fun with it it as the ball starts rolling.
This is a work for fans who want to see the early Block in action. His later works are vastly better developed and more sophisticated. That said, it is interesting to see what he was like in his early days. If you like reading some of Ed McBain's early 87th Precinct novels and seeing how his work developed, you'll get the same sort of kick here.
If you're new to Block, go pick up 'Like a Lamb to the Slaughter', 'Eight Million Ways to Die', or 'When the Sacred Ginmill Closes'. These are all works of true refinement in the crime genre.