My friend installed it by accident instead of the normal one and I just clicked buy out of curiosity to see how much it was, thinking it might be like £50 or something, so we were quite shocked to see that it was £200 per year.it offers garmin gps integration. you plug the garmin in, google sucks the data out and plots it onto a sexy google map. there are obviously other benefits - but gps integration is the best I think. Personally, considering how nice the integration is, for professional usage its easily worth the £200. I bet you get some other cool perks too
/edit - its not jsut garmin, but I have a gamrin gps so thats what I know