We have the RV760 and have been happy with it. Thanks to my back surgery, we won't be traveling for a while. We did use it on one short trip where we knew the route and it was spot on. The internal antenna works well. I use the Garmin bean bag mount and set it on the center console of my truck and it keeps perfect reception. I agree with a couple others...read the manual. I have found that nearly every gps issue I've had over the years was solved when I broke down and read the manual.
I got mine from Best Buy since I had some reward cash to use. It was under $400 with free lifetime maps.