I had read it once a few years back; this time (I'm on page 465 of 620 - not counting footnotes, bibliography, and index; McNally does have a PhD in history, after all.....) is reaffirming my earlier opinion that it's well worth the read. But don't take my word; here's Robt. Hunter's blurb from the back of the dustjacket:
"This is McNally's view of what went down. It's more often right than wrong and done with love, not a grudge, which goes a long way toward excusing another damn book about the Grateful dead. Any view of us is necessarily a limited interpretation, like an aerial photo of Ground Zero. What Dennis loves and hates about us bears more weight than most interpretations because he took twenty years to get his facts straight. I'll miss him when we kill him."
I presume that the "grudge" remark is a dig at Rock Scully's pathetic screed Living With The Dead; Twenty Years On The Bus With Garcia And The Grateful Dead; I cannot recommend that one at all, but I cannot recommend this one highly enough.
Peter (who also advises not wasting time on Cindy Brightman's Sweet Chaos: The Grateful dead's American Adventure)