I assume you’re talking about driving. To me Google Maps has worked well when walking around Tokyo, particularly when finding small, hole in the wall ramen shops off the beaten path. I haven’t used it in the city for driving but it’s worked well when going to rural onsen locations. And I prefer it to the rental car’s built in navigation system (which is almost always a Nissan Note).

There is one time it really screwed up. I like walking along those micro streets, lots of interesting stuff to see in neighborhoods. My wife and I were pushing out baby in a stroller and Google maps route sent us along a path that included a giant steep flight of stairs! It wasn’t a big deal by there was no mention that the rout would be in accessible to people who couldn’t climb stairs.