First, I like it about Ondaatje that his books are all completely different from each other.
Divisadero is a classic case of a "French novel in English" -- on many levels it feels more like a French novel than an English one. Early on, Ondaatje says of mid-twentieth-century Northern California that, "It was as if there were a novella by Balzac round every bend," and so it turns out.
This book's written in the sort of poetic prose that only poets can write. (Non-poets can write poetic prose too, but that's different -- Divisadero is written in sound, disciplined prose that you can nonetheless feel constantly yearning to become poetry.)
The first two thirds of Divisadero feel to me like a rare case of a novel where each chapter has the strengths of a short story, even though, cumulatively, the chapters combine to achieve the virtues of a novel. This part of the book's set in twentieth-century California and Nevada, but through plot and imagery Ondaatje keeps one foot in the pre-modern -- nothing happens that couldn't just as well have happened in fin-de-siècle rural France. Reminders of the beauties and violences of pre-modernized society are constant throughout the book.
The last third of Divisadero shifts completely to fin-de-siècle rural France, leaving key characters in the lurch, the focus shifting to someone who previously seemed to be a minor character. As anyone who's written novels and gotten feedback on them might suspect, this throws certain readers -- David Wildman took this point up with Ondaatje in an interview, which contains some more plot information. Somehow the effect of the shift pretty much works for me though. (I know "somehow" is not a very satisfying explanation, and if I come up with a better one, I'll come back and add more comments.)
"Succinct histories tell us something -- that anything peaceful has a troubled past." -- Divisadero