I still believe the most important part of any trip is planning before you leave! The GPS is a great reminder of upcoming turns, what lane to be in and the last turns to the final destination, but I already know what route I plan to take just in case the GPS decides I should take the route through downtown Toledo instead of the Interstate around the town (true story!). The live traffic data alone is worth having the system running. Someone posted earlier asking how much data was used. It is an extremely small amount. I measured it once a while back and I think a 250 mile trip used about 250 MB.