This is big concept SF, and the idea definitely has enough punch to ensure a satisfying read. Touching on mental health and the concepts of reality in this context certainly brings up some interesting concepts for the reader to mull over.
Dick re-creates a 1950’s middle class America in all its consumerist glory and immerses the reader in Gumm's reality as it begins to unravel. A novel deep with intrigue it progresses at pace, driven by the paranoia's hold on Gumm. The seemingly serene setting makes the revelations contained within the novel all the more terrifying.
Deep with philosophical musings on reality, the tensions build to a satisfying conclusion, tying together all the little clues laid down expertly by the author. A quick, thoughtful and satisfying read.