Comment I did it (Score 1) 81
I had that device plugged in for six months. During those six months I made a round trip to Florida. Most of the trip I was going at least 80mph, sometimes 90 and occasionally I exceeded 100mph. It was all recorded and displayed in the graphs on the web site. Overall, I drove like a speed demon, but my hard stops averaged to less than 0.1 hard stops per hour of driving.
After the six months were over, my insurance rate went down 27%. My insurance rate was already fairly low to begin with, so 27% amounts to just a few dollars per month.