I've been mulling a GPS for the past year, but I'm a cheapskate. I drive pretty close to 60k per year, but know my routes by heart. I've borrowed a neighbors Garmin Street Pilot and found it incredibly annoying when I know the route I need to take. Enough to pull it out of the window.
Borrowed it last week on a first time trip to Cin, OH. Programmed it enroute on I70, my first mistake. Chose the wrong street and ended in on the North side of Cincy vs. the SW side. That stupid mistake cost me 45 minutes and an GPS routed trip thru a pretty nasty part of Cincinnati.
But, didn't have one last week in Utica NY. Decided to take in a movie before checking into my hotel. Pretty much got disoriented leaving the theater at 11 PM and went 45 minutes in the wrong direction. GPS would have saved me there.
My other downside is one more thing to take out of the car when checking into a hotel for the night. Stereo headunit, XM, laptop already, now a GPS?, sheesh.
