The friends with whom I ride who have the Varia don't do much with the data, or at least I don't see them react to it. I am quite comfortable riding further out from the shoulder/curb when I am pulling, even taking the whole lane, especially now because of salt, debris, and possible ice patches from refrozen melting snow on the bank. Them, not so much, and most will stay at or inside the fog line. I also consider the direction of the side winds when pulling. E.g., wind from left, I ride further out giving riders behind me a better angle, and vice versa. A few of them have even said they don't feel comfortable riding further out from the shoulder. I don't notice them deviating from their path when there is an approaching vehicle. But none of them have logged as much mileage as I have on the road, and have had to deal with as much traffic as I have.
If you actually use the information the radar gives you to ride proactively and adjust to the changing conditions, then it's a good safety device.