The problem for RVers is that we tend to go places that are remote and in this case that means no cell signals for ANY carrier. We've used Garmins for years and our new Garmin 2757 is wonderful and a huge improvement over our older ones. We tried a height POI and decided it wasn't useful - which is good because it was shortly discontinued! :
With any electronic device you have to use common sense because none are 100 percent reliable. The mapping has improved considerably. Our new map no longer takes us into a bridge abutment in Eugene, OR, to a wall with Walmart on the other side, or down/up a canyon with no road near Mt. Lassen. There are errors in any system, but not as many as previously. It's impressive that the 2757 tells you to turn at the stop light before Appleby's or you see various buildings labeled with store names when you look at a shopping center. The 2757 is far superior to any GPS we've had in cars so we carry it back and forth between them which means we don't have to learn another mapping system and quirks.
ArdraF