I can report from the city of Basel: yes, the GPS is not that accurate. As soon as you get close, you can search via Bluetooth. Which then works pretty well.
Our most frequent problem is that our cat loses the collar in the backyards. Since the GPS is not that accurate, you first have to ring a neighbour's doorbell to find out via Bluetooth that the collar is two gardens away. So the collar is perfect in the city to get in touch with the neighbours. Nevertheless, we really appreciate it because of the long battery life.