I found reading these letters (and I haven't read any of the earlier volumes) at times tedious, at times revealing, at times surprising, and at times humanising.
To me Philip Dick has been something of an icon from when I first started reading him in the 1970s - initially through the short stories (for one of the less well known that I admire so much consider 'If there were no Benny Cemoli' - which you can find in 'The Preserving Machine' amongst other places). The first of the novels that I read was 'The Man in the High Castle', and, although I don't see it as really typical PKD, it's little surprise I hungrily read them all as they became available (even the ones PKD - in these letters - disparaged, such at 'Puttering around in a Small Land' - Hollywood producers could learn a lot here). One of my favourite PKD novels - not critically admired but I think worth a fresh look, is 'The Penultimate Truth'. And, of course I have absorbed all the extras I can find - the 'Exegesis' extracts, the essays and introductions, the biographies, the film adaptations .....
I did find these letters increasingly emotional to read (when I skimmed the 'endless' speculations on the nature of reality, the structure of the Universe). What he didn't know, but what I did know, is that these were some of his last writings - he didn't know the end was so near.
Because PKD was such a diligent researcher and explorer he introduced me to many concepts, including the concept of empathy. One day I picked up a novel in a bookshop by Rabindranath Tagore and it seemed to me that this was someone PKD may have used partly as a model for a character in one of his novels - my interest was immediately stimulated and started a love of Tagore's writing. But I was mistaken! The character PKD had wriiten, and I had confused with Tagore, was Mr Tagomi in 'The Man in the High Castle'. How surprised was I when I read in his letters that late in his life PKD had a revelation of a Christ-like figure dying at the time in Sri Lanka, a saint called Tagore!! PKD probably did know of Rabrindranath Tagore but there is no apparent connection with the revelation of the saint in Sri Lanka.
I was dismayed to read of the bullying PKD got from his publishers late in his life even though by then he was a demonstrably successful writer. In reading a biography of Joseph Conrad I read of the same stress that Conrad had experienced. I'm sure this pressure does at times compromise a writer's output. (Conrad rewrote the second half of 'The Secret Agent' after a rushed first writing to satisfy the publisher - I think it shows so clearly.)
But, perhaps the most surprising aspect of these letters is PKD's repeated complaint that he was hopeless at dreaming up titles for his novels, short stories. For me, a title such as 'Do Androids Dream of Electric Sheep' or 'The Man whose Teeth were all Exactly Alike' are such seminal PKD titles. They totally capture the author's humour with its dark (but never blue) side. If PKD didn't write these, who did??
The only negative I have about these letters is that they are rather like overhearing a mobile phone 'conversation' - a half-a-logue. I would have loved to read some of the responses PKD got - including from the CIA, and from Ronald Reagan.