I only have experience with Garmin and would replace the current units (2 of them) with updated versions when the time comes. One is 10 years old and the other is about 6 years old I think. The newer one has lifetime maps and traffic so unless it stops working I have no reason to replace or upgrade it. I didn't get it with Bluetooth (for phone calls, etc) but most cars have that now. I still think it's more flexible that the built-in units in the Cadillac and Volvo.