My experience was back in the 1980s. No laser then. I had a the best unit, an Escort brand. For speed traps where the cop sat with a live broadcasting unit, it detected every one of them and I never got a ticket from one. Instant on was another thing. It worked by placing a dummy load on the transmitter until the cop saw a speeder and switched to transmit to clock someone. Most cops were too trigger happy with instant on units. I usually detected them clocking cars ahead of me; so slowed to the speed limit and never got caught. Some instant on units leaked some radar….you’d get warned with a weak signal that became very strong when the cop eyeballed you. I beat all these speed traps too. Only twice in several years did I come eyeball to eyeball with an instant on and get nailed. The cops were so proud of catching someone who ran with a radar detector.