I don't know... I don't think that the point of a leash is to know where your dog is but more to keep him under control. This does nothing for that except ring bells and stuff which can be more annoying then helpful.
I too don't like the name that they've given the "leash" feature. It seems like it just alerts you when your dog has gotten away... which is often too late to do anything about.
The problem for me is that I already know he is missing, and this thing doesn't tell me where he is.