We've been using it for the last two years - IMHO best planning tool around. Since it's an overlay on Google Maps, it's always as up to date as Google.
The daily mileage radius is my favorite feature - based on mileage, planning each night’s stop is simple - the program has a huge database of campgrounds.
Since it's subscription based, you do have to pay a yearly fee but it's cheap for the great tool!
Mike