Well, I've been using radar detectors for 10 years now and have saved much $$$. I am an aggressive driver that prefers the long way if the road is truly a 'road'. I tend to live near classic country roads which the local sheriff uses radar (K and Ka band). Also, the California Highway Patrol has been authorized to use radar on certain freeways/highways near by as well.
I used an early model Valentine 1 that worked great; I liked the front/rear antenna feature which provides "threat direction". The V1 needed to be repaired and Valentine was going to charge me 200 USD
. Even though it would be upgraded with Laser detection, I passed. Based on test reports from RadarTest.com (http://www.radartest.com/DS4HEM.html
) I chose the Escort Passport 8500.
On a recent 1400 mile trip, through several states, the 8500 paid for it's self many times over. As I use the detector on the streets in my neighborhood, I've noticed that though the 8500 does not have a rear antenna, it has detected signals from the rear quite well. All in all, I'm very happy with the 8500.
My two cents ...