Have used a garmin 760lmt AND a garmin 2555lm AND copilot (with dimensions loaded) on an iPad for 2 months continual travel. The 760 has consistently sent me into low height and overweight situations in spite of it being loaded with dimensions and on rv profile. Frankly I doubt that it uses the information. The disclaimers when you turn it on make me suspicious. I don't any longer use it for navigation but it is nice to have with a map view and to find Starbucks. Waste of money. But copilot on the iPad is brilliant and is used by our human copilot