The biggest complaint that I've heard about it is that, while it's very detailed in the six key events that he chose to cover, he's very brief on the broad strokes that give said events some context.

I question the periods he chose to cover, too. I don't think any book can claim to be a comprehensive history of Rome while beginning with the reforms of the Grachii, and it does focus exclusively on the imperial period and the events directly leading to the rise of the first princeps.

Baker says that Augustus was treated like a god, and while that may be true in the eastern provinces where god kings had a history, Augustus was firmly opposed to being treated as such while he was still alive. He most definitely wasn't addressed as that and the name was entirely foisted upon him by the Senate.