We use two of them...the built-in one in the coach (Jensen, I believe they use the Navteq maps) and a Good Sam Rand McNally 7" unit. I use the Good Sam site to plan trips and then download them to the Rand unit. I use the two of them together...if they don't agree, we get out the tried and true maps. The Good Sam Rand McNally unit has been right more times than the Jensen... The Good Sam Rand unit is easy on the eyes, we like the display of turns and route changes and at 7" it only takes a glance to "get the picture".