Got unit yesterday, I think I am going to really like it. It has a feel of quality compared to the 8500. Most of my driving is suburban with some highway, but not open road. There are 6 or 7 radar speed signs each way on my daily commute to work. After marking them last night on my trip home, it was a quite trip to the office this morning. I had to make a cell phone call, and my car has bt handsfree. Usually I have to quickly hit the mute key and the caller on the other end gets to hear the alert. Not this morning.
My impression is the sensitivity is at least as good as the 8500, at least on K (radar speed signs). Now when I get an alert on my way home, I will know it is likely one to be paid attention to.
I also like the auto brightness and auto volume. Unless there are some glaring faults in sensitivity that I haven't seen yet, I am going to love this detector.