I hooked my 550 up to the computer and started to do the Garmin update for grins. It first installed the map installer or did something that updated the 550 so it now says 2012 when it boots up when started. So far that didn't cost a thing so I stopped right there. Hopefully it updated the firmware or software or whatever makes it work and seems to work good but I haven't had in on the road yet.
My thinking is that they haven't changed the road system much since the 2009 maps mine has on it. Maybe to find a new street address or someplace new but I'll try it this way for a while. I am cheap and considering a 660 anyway.
The biggest hassle I had was riding down a state or back road highway and the GPS not showing the road. What's up with that?? I always have a paper backup in the tank bag. Maybe the free 2012 issue/update will fix that.