I've had my detector for a couple of years now, as I have to drive through a small town noted for its aggressive speed enforcement. The "instant on" can be a killer, as you don't know until it's too late. I'm careful to maintain the posted limit unless there's at least one vehicle in front of me, even if it's several hundred yards. That way, my detector will pick up the short bursts targeted at the lead vehicle. This happened to me just last night. The car in front of me was going the same speed I was, maybe 5 mph over. A cruiser coming the opposite way blipped my detector for about a half second. Sure enough, he turned on us and nabbed the guy who was in front of me.