I was traveling on my favorite stretch of highway for moving Ka when I got a 2-3 second 2 bar alert. I zeroed my trip-odometer. About a 1.7 miles later the LEO passed me going the other direction. I was close to the PSL, and with him likely doing the same, he was likely equally distant from our meeting point as I was from when I set the trip-odometer. That would make the range about 3.4 miles.
The RD was lying on the dash about 2 inches above the hood line, so I feel pretty good about this unit's ability to detect Ka.