This is probably the weakest PKD book I've read. Not that it was especially bad, it just didn't really work for me on any level.
At no point did I find myself particularly engrossed and enjoying the story. The narrative, fragmented by numerous points of view of the disparate characters whose futures eventually become loosely entwined later on in the novel, and punctuated by random time intervals between chapters, it didn't flow well at all, especially for the first half of the novel.
Here are some familiar themes such as mental illness, paranoia and megalomania and other new ones such as a post apocalyptic scenario, not one but a couple have already happened and another unfolds in the narrative. Also, a full range of psychic powers are explored such as telekinesis, telepathy, future visions and communion with the dead.
One can usually expect a mish-mash of ideas in a PKD novel but they didn't really come together very well here, as he somehow manages to pull off elsewhere. There was a wry humour throughout that occasionally made me chuckle though. All in all, not a book I would particularly recommend.