Based on my experience at home and on the road, I am convinced RVers are pretty much washed up with the new free airwave digital technology, no matter what antenna they get.
Any near by obstruction between you and the point of origin, and you are done. Any mountain, forest of trees, building, bigger RV, and you have no signal. If you don't know where to point, you're done. Especially if you have to scan for stations, where do you point the antenna to start scanning?
We were in Las Vegas. In town at the KOA, I got one good station, and one pixelating station. The problem is that you have to rotate the antenna precisely to the signal's point of origin, then scan for stations. It is extremely touchy. A few degrees off and you missed it.
It is the same at home for my roof top, I bought the best available digital antenna,
This One here. It has a 70 mile range, but we are only 35 miles from the Sears Tower. What a joke it is for us. This fancy digital antenna looses the signal with the slightest movement or change in cloud patterns. Any breeze and the picture pixelates and looses sound. We live in a valley without line-of-sight, so we are done with free airwaves TV. Not so with the old analog technology. When it was weak, you had a little snow, yet still decent sound. With digital, a weak station gitters the picture, and the sound immediately cuts off. There is no forgiving with digital technology.
It is great for people who have line-of-sight toward a large city. For everyone else, it's bad news.