His Leonardo biography is mediocre at best. It may read smoothly but he lacks a good grasp of the subject matter. Instead, Leonardo is like an earlier Steve Jobs of some kind.
Could you recommend a better biography from that period?
I think those biographies are more pop than his fans like to think and more academic than his detractors might imagine.
Things that happened, happened. Most of all when reading popular biographies I want to be introduced to real things that happened, and if some of that draws my interest, I can then dig in to more academic sources.
The popular biographies offer the '100 feet' view over their subject and the society in which they lived in, and should not be disparaged if they succeed in doing that in a readable and entertaining manner.
That's a rare thing, though. The adjective should probably be used neutrally way more often than derogatorily.
I suppose the the biographies would need a more detailed critique of what people did not like in them to say anything particular about one of them.
Jobs biography alone does not give a sufficient image of the man, for example. But when combined with "Becoming Steve Jobs" the picture is more well rounded. That does not mean I did not enjoy the book.