It depends.
Even with every and best counter measures, one has to exercise judgement on where to speed.
Constant-on radar signals are useless against top tier RD’s. It’ll alert driver up to few miles away.
Instant-on radar signals are much deadlier. You’ll likely get caught if, just so happen, you are the the cop’s first target....if you have a top tier RD, and cop is already shooting at cars up ahead of you, the RD will pick up on even the momentary signals.
Laser signals....need Laser Jammer for that. But Laser does require officer to accurately point at a reflective surface of your car (headlight, grill...), also needs a direct line of sight, and the cop has to be stationary; therefore the cop will be more visible. Cop can’t just be driving along then flip on the laser to get a reading.
My experience: RD has done me well, easily paid for itself 4-5 times over. Yeeeears ago, I used to drive from Dallas to Galveston (320 miles door to door) every weekend. I would depart Friday night around 9pm to ensure clear road. My Escort 8500 (top of the line back in the days) not only saved me, but also the driver behind me one time.
I used to feel the same way about RD, until my first speeding ticket....my second trip to Galveston, doing 90 ish in a 65, F150 following me....then all of the sudden he slowed down.....I kept going like a dumbass.....about 10 seconds later, cop sitting on the side way ahead, turned on all the lights, got me so dead on, I just stopped behind him voluntarily. Clocked me at 97.
That one ticket could’ve paid for the detector.
ticket was $387 or something like that.