I have been told by an acquaintance who happens to be a state cop that most
of the time you have about an 8 mph cushion before they'd go to the trouble of pulling you over. So long as you are driving safely. Unless you're somewhere that's doing some sort of zero-tolerance campaign on speeding, which does happen on certain weekends.
What will get you pulled over in a hurry is any sort of wreckless or dangerous driving. Swerving, tailgating, etc, those will be ticketed. And I agree 100% with that.
The primary reason I drive on long trips with my detector is for the entertainment value. Seriously. Anything to break up the monotony of the 800+ mile drive that I have to take to visit my in-laws every month or so. I'm not even speeding, but I like the fact that I'm given some warning as to where the speed traps are. At least I know when to be alert for an officer standing on the side of the road writing a ticket, and can be ready to move away from his lane ahead of time.
There are also many places where the flow of traffic is considerably
faster than the speed limit. For me, the major highways around the Chicago/Milwaukee area are a prime example. Very often the speed limit will be 45, 55mph. Very often the flow of traffic is 70mph in the slow lane, and 80mph+ in the fast lane. Driving 45mph when the traffic around you is doing 70+ is a recipe for disaster. On some weekend where the Bears beat the Packers, and I'm driving through Milwaukee with my Illinois license plates, how do I know that some Wisconsin state cop isn't going to take that out on me?
But even though I own and enjoy using my detector, I will go so far to say that its usefulness for the hard-core speeder is greatly diminished these days. At least from my experience in Illinois and Wisconsin, many speed traps now use laser instead of radar. Not all, but a lot of them. The X50 will alert you to lidar, but at best it's really only going to alert when you are within a second or two of being hit. Usually the alert just means that you can look down at your speedometer and know what the officer is seeing on the lidar unit.
Since the laser beam is small and contained, detectors can't 'sniff out' a laser signal like they can a radar signal.
Of course, there are still many traps done with radar, and the detector works great for that. Any moving patrol will be via radar because they can't shoot laser while moving.