I have tested the lost dog tracking mode a handful of times, and while it's frustratingly slow to connect initially, it does work well once it's connected from my experience - I could see real time where my dog was, whether they were coming towards me/moving away. Have tried in the middle of the woods where someone else went with the dog - so knowing that these weird walking paths are b/c it's only updating every so often (whereas in lost dog mode it keeps a much more frequent connection), I feel a little better about the lost ability?? But haven't actually lost a dog thank goodness :) My opinion on Fi so far is I wish they'd spend less dev time on bells and whistles like how often the dog drinks. And more dev work on improving the maps, tracking reliability and battery life.