If you don't ride, please don't post about how stupid this is. As rider, daily commute and touring, I can say that a GPS unit is a great addition to a motorcycle. It's certainly not for the daily ride to work, or short around town trips, but on longer riders (I just got back to Minneapolis from Tucson) it's a real godsend. I used paper maps for many years and while riding it just takes too long to focus on the map, determine your position, and plot your next turn. Even with printed out turn-by-turn maps it take your eyes off the road too long to read effectively. With a good GPS unit you can very effectively, and safely, navigate unfamiliar territory and not divide your attention between the inattentive cagers trying to run you off the road and route to your destination.
I am currently considering getting a more motorcycle focused unit (Garmin Zumo 550) to replace my current riding GPS (Garmin eTrex Legend Cx). This TomTom unit seems to be adding exactly the primary feature I am trying to get, namely a clear, uncluttered display. On a motorcycle having just the information you need to better than having too much info.