Considering he was a personal friend, it would be very easy for him to just mythologize Joe. He could have very easily just emphasized his good characteristics and glossed over his negative ones. Of course - Joe had his faults (like any of us do), and Salewicz is the first to point these out. It makes his book all the better. A hagiography, this most certainly isn't. And because I knew so little about Joe before reading this book, it was an incredibly eye opening experience. Here his failings are made clear, although never in a way that feels merely like a disrespectful slamming of a dead man. You can clearly see how much love Salewicz had for Joe which makes the objectivity displayed all the more impressive. In reading it though, I came away feeling like I knew the man better, and the book is an incredibly worthwhile read for that. Salewicz's admiration for Joe jumps off every page but it never shrouds the objectivity of the book. Also - he treats the other members of The Clash in a similar light: never taking one side over the other when discussing their turbulent fallout. I actually came away from the book admiring all the members of the band more for one reason or another, whilst feeling like I had a better grasp of what happened.
Another thing I love about Redemption Song is that it highlights that, yes Joe was a great frontman: but he was also dogged by insecurities and even depression for rather lengthy periods of his life. We follow his journey from rebelling against his upbringing, to squatting in London whilst playing with The 101ers until one fateful night witnessing a Sex Pistols performance makes him realize that punk music is the way forward. An utterly human depiction. And as The Clash becomes more successful, Joe is wracked with doubts more and more about whether or not he's a sellout. The book paints The Clash in a very favorable light in that regard; as a group that cared about the image and messages they would give to fans, and as a group that never saw themselves above their fans.
Although don't think that just because The Clash ended doesn't mean the book becomes dull and uninteresting. For me this is when Redemption Song becomes especially fascinating. He would spend the rest of the 80s and pretty much all of the 90s in relative obscurity, until his resurgence with The Mescaleros. After two great albums, he died so suddenly, If that sounds depressing though, I actually got the feeling that when he died he was the happiest he'd been in years, you can't really ask for more than that can you?