We've got the RV 760 with the backup camera and are real happy with it. Local searching just involves typing in "Walmart" and it comes up with the closest ones to your location and you can select one to go to.
Our current location is The Vineyards Campground in Grapevine TX. To find it on the GPS (we were in Hot Springs, AR), we typed "vineyard" in the search box and then "grapevine tx" in the area box and it came right up.
So far we have used it for 1900 miles in this trip out west and it has performed flawlessly. Directions are clear and ample warning is given for lane changes, etc. Examples: turn left at the traffic light, be in any of the 3 left lanes, take the ramp at exit 4 and be in the left lane.
And we use the Bluetooth phone connection to make\receive calls.
The camera grid lines are adjustable both for left/right and start and stop distance on the zones, making it highly accurate.
Good luck with your decision...hope this helps some.