I have noticed that the area filtering when you are browsing other people's activities on Garmin connect is a little patchy. For example, if you enter "New Zealand" as the search string you only seem to get activities around the middle of New Zealand (e.g. lower North Island and Upper South Island). I presume that this is because the site geocodes New Zealand to a fixed point and then searches within a fixed radius around this point.
However, the point is that it results in a pretty poor user experience. It would be nice if the user could control the search radius and it should be pretty easy to implement :)
Thanks
Andrew