A few comments regarding Tom Tom (BAD) and Garmin (Good).
We have both a Tom Tom unit, and a Garmin, both with up to date maps.
We confirm what is widely discussed in GPS forums: Tom Tom maps are often very inaccurate for North America, but are far more accurate in Europe. This is due to Tom Tom sources its maps from a Europe focused map provider.
Garmin maps are generally far more accurate (than Tom Tom) for America’s region.
I would never again buy Tom Tom for use in America.