Since no one else has finished reading this yet (I mean, in the world of goodreads), I feel a little obligated to write something about it. Here's my review: this book is wonderful. I picked it up a few months after reading the new edition of Weschler's book on Robert Irwin - Seeing is Forgetting the Name of the Thing One Sees. Although the Hockney book is set up as a companion to the Irwin volume, I found it even more enjoyable and thought provoking. Not that they shouldn't be read together (both books definitely center around some of the same basic questions about perception and artistic representation) but the Hockney book is just more fun. The chapters on his foray into art history and the development of his theories about the influence of lenses and projection on early Renaissance painting read like detective fiction. I mean, ok, nerdy detective fiction, but still.
Here was the major difference for me between Seeing is Forgetting and True to Life. Following Irwin as an artist and a person made me want to sit back and contemplate a bit (it also made me want to drink a cold Coke - like, really bad). Overhearing Weschler's conversation with Hockney made me want to go and look and look and look at paintings. That's it.