So far I'm really enjoying this as I've enjoyed mostly everything by Murakami I've read previously. Bonus points for it being such a long audiobook (46 hours) and having two really good readers. The shifts into alternate realities have been rather subtle and the characters have reacted first with the belief that the differences in universes were always there and somehow they'd just overlooked them which seems an imminently reasonable response. I'm intrigued to see how the two characters will intersect as their paths are so different but also tinged with the tiniest of overlaps. Murakami's flat, matter of fact delivery is a deft tool to deliver the more incredible events in his fiction.
There was a moment where I started to flag in my concern for the two leads, as the action seemed to be in a holding pattern. It seems the author sensed this too, as a third narrative perspective started, and the book regained its early energy. But the end fell kind of flat for me. I don't want to give any spoilers but it all closed much sooner than it seemed the storyline required (at least as far as I was anticipating).