The problem is that I believe most people who have one will be a little more gutsy in driving faster, which is a big no no. Cops can use instant-on or quick trigger radar and still get your speed and your detector might not even go off..

They can also pace you, etc. They will indeed help but in no way guarantee to alert you to every police radar signal.

They are indeed great tools, but they also instill a greater confidence which might not always pan out.