The trouble with books that change dramatically part of the way through is that sometimes they lose you. This is what happened to me. As much as a loved the characters, setting, plot, place.... well everything really of the first 100 or so pages.... I was lost when main characters moved from bustling England to quiet Australia.
The book itself didn't become any less excellent... rather I just became less interested in it. As a rule I'm not much for historical novels and this is as close as I've ever come to falling for one.