I've also read Parrish, McNally, & Scully. McNally's was definitive, Parrish's book was clearly not ghost written. It was honest and came across as essentially accurate and entertaining. Scully's book contained some inaccuracies, including a description of a concert on Jerry's birthday where, according to Scully, it rained, the band couldn't play because of the electical danger, cancelled, and the audience rioted. Rock must have been on some heavy drugs that day. I was there. It was rainy, but there ends any semblance of reality in Rock's version. The Dead played, no riot ensued.
The thing that I loved about Phil's book was that he seemed more interested in the music itself. The kiss and tell and other historical stuf was only included, to the limited extent it was, where it was needed to put in context what was happening musicially with the band. The other books attempt to tell the history of the Grateful Dead. Phil's focus is more on the history of Grateful Dead music. As a musician, (and as one who loved the Dead but was less loving of the deadheads, especially from the 80's on), I found Phil's analysis of the music fascinating. Even the name of the book Searching for the Sound bears out Phil's concentration on the music itself.
Bill, tgo