Most people I know use the Valentine 1. I love that it can detect laser or radar in front and behind you. It read various signals and can tell you the radar/laser type (garage door, traffic light, call box, laser, radar gun.) The signal strength is either illustrated or auditory (you control the volume), and it will display where the signal is coming from, front, lateral, or behind. It can also detect signals that have bounced off of other cars in front of you, especially if a gun is used from the roadside- picking specific cars.
This unit can save you time and tickets!
It also pays to use common sense while driving. If you are the lead car you must be more careful! Any gun can snag you if you don't slow down while coming up on blind corners and elevation changes. But, if you are not the lead car, or are weaving thru, the detector/locator will serve you well with it's ability to read signals that rebound off the other cars.
Don't buy the cheap units that do not actually locate the signal!