That review's a bit harsh, but mostly correct. Reggae Heritage is not a great example of writing, but if you can look beyond that and some of his opinions and agenda you do get an account of a crucial piece of sound system history that hasn't been written about in much detail but is of great interest. If he didn't write it, perhaps nobody would have, and the information would have been lost.
I can't stand the style of most reggae history writing, but as with this one, even if you don't like all he has to say, he was there, and has as much right to have his say as anyone else. Most history is written by people who did not have first hand experience of the subject they're writing about, so any details from the people who took part or witnessed it are to be cherished.
I'm looking forward to reading the Studio 1 book. Bits of it will annoy me, but I'm sure I'll get something from it.