I have had 2 Garmin GPS's and was looking to buy the Garmin 760 for $399 because of the RV data that can be inputted. After some posts here I decided to try the Copilot app for the smart phone for $6.99 which can input the height of your MH to avoid low bridges and also has a feature to avoid tunnels that do not allow propane. It essentially does the same thing as the Garmin and Rand RV specific GPS's for a lot less money. The phone itself has a built in GPS so you do not need cell service,and does not use your data only satellites like a regular GPS. So far I really like Copilot App. Where I am staying now in Fla. my Garmin was always about 1/4 mile off(close enough) the Copilot is right on.