I have had four generations of Garmin GPS devices and still have the last relatively recent one.
But, I wouldn't invest in a GPS company. I increasingly depend on my smart phone and Google Maps. The biggest frustration with a GPS is the difficulty of finding a destination (i.e. describing your destination in a way that the GPS will find it) as opposed to Google Maps and the sophistication of Google searches. It is like night and day to me with Google's anticipation/suggestions as a search is entered.
Smart phones just keep getting better and are leaving dedicated GPS units behind in my opinion. Yes, they still have a few limitations but they are quickly going away.
