I enjoyed all four--especially the last two. My only complaint is the endings which aren't nearly as good as the rest. It takes a little time to become familiar with Dick's made-up words. He doesn't define them for you. However, he uses the same words in multiple works so if you have read some of his writings, subsequent stories are easier to understand from the outset.
One thing that is fun to do while reading old science fiction is compare what the author thought the future would hold to how things actually are. Most of these novels take place in the 1990s and all were written in the 1960s. Naturally, space flight was all the rage then so Dick envisions far more happening in space (colonization, etc.) than is really the case. Some things he predicted very well such as video conferencing and phones in automobiles. Others he was far too conservative on like music still being listened to on albums. There is no mention of anything even remotely resembling a PC or even a mainframe computer. Perhaps that would be different had he written these in the 1970s instead.
I found all four of the works to be thought provoking. They provided timeless insights on the human condition. I especially recommend reading the last two if you are on a trip by yourself (like I was when I read them).
Finally, there are some very interesting notes and a Philip Dick biography at the end of the book provided by Jonathan Lethem.
If you like this book then next on your reading list should be this follow up compilation.
from the publisher:
Known in his lifetime primarily to readers of science fiction, Philip K. Dick (1928–1982) is now seen as a uniquely visionary figure, a writer who, in editor Jonathan Lethem's words, "wielded a sardonic yet heartbroken acuity about the plight of being alive in the twentieth century, one that makes him a lonely hero to the readers who cherish him."
This Library of America volume brings together four of Dick's most original novels. The Man in the High Castle (1962), which won the Hugo Award, describes an alternate world in which Japan and Germany have won World War II and America is divided into separate occupation zones. The dizzying The Three Stigmata of Palmer Eldritch (1965) posits a future in which competing hallucinogens proffer different brands of virtual reality, and an interplanetary drug tycoon can transform himself into a godlike figure transcending even physical death.
Do Androids Dream of Electric Sheep? (1968), about a bounty hunter in search of escaped androids in a postapocalyptic society where status is measured by the possession of live animals and religious life is focused on a television personality, was the basis for the movie Blade Runner. Ubik (1969), with its future world of psychic espionage agents and cryonically frozen patients inhabiting an illusory "half-life," pursues Dick's theme of simulated realities and false perceptions to ever more disturbing conclusions, as time collapses on itself and characters stranded in past eras search desperately for the elusive, constantly shape-shifting panacea Ubik. As with most of Dick's novels, no plot summary can suggest the mesmerizing and constantly surprising texture of these astonishing books.
Posing the questions "What is human?" and "What is real?" in a multitude of fascinating ways, Dick produced works—fantastic and weird, yet developed with precise logic, marked by wild humor and soaring flights of religious speculation—that are startlingly prescient imaginative anticipations of 21st-century quandaries.