I read The Godwulf Manuscript shortly after it was published, and I was hooked. I read every succeeding novel that Robert B. Parker wrote, and I loved 'em all. It didn't matter to me what the reviewers said about them. All that mattered was that Parker kept writing books, and I kept reading them. Why? Well one answer might be the one that Lawrence Block quotes at the beginning of his essay on voice in this collection. It's not exactly as I remember it, but ever since I read it, I've used it again and again to talk about Parker's work. In fact, I've probably used it in this blog a time or two, so I'm not going to quote it again. You'll just have to read the essay.
I was a bit skeptical when I heard that Ace Atkins was going to continue the Spenser series after Parker's death. Maybe more than a bit. After reading Atkins' essay here, however, I've become less so. If Parker and Spenser have meant so much to Atkins that I'm convinced he's the man for the job if anyone is. Anyone other than me, I mean.
Ed Gorman offers an interesting take on Parker's westerns and the western in general. He mentions that some of the Spenser novels could function as westerns, which is certainly true. One of them is The Magnificent Seven redone with Spenser. I don't think Gorman mentioned that, though.
Max Allan Collins and Matthew Clemens have an excellent overview of Spenser on television with summaries and comments on the shows. They even provide a complete listing of all the Spenser incarnations on TV at the end of their essay.
There's lots more good stuff here, and the book is highly recommended for Parker fans. Those only casually acquainted with his work will find Penzler's introductory essay helpful, but they'll also find plenty more to like between these covers.