I have both a Walmart cheapy and an Escort. Both work on the majority of radars in my area (k, Ka band). The pricier escort will detect all bands 4times as far away as the cheap one. The cheap one will pick up several hundred yards away on flat land. The Escort can pick up 1/2 mile away easily in hill country and much farther on flatland. The problem is some agencies use pop and laser radar detectors and your radar detector can't detect what is not on. You might get lucky and the cop try to hit someone with the laser out in front of you and it set your detector off alerting you to the threat. The best advice is to stay under 8 over and you'll avoid most tickets on the highway. I try to keep it under 5 over in the city. I use my detector mainly to keep me alert and have hit the brakes only to look down and I'm already running right at the posted limit. Police can time you between to known distances via the air or parked cruisers. Some locations use video assisted traffic patrol that are very efficient at catching would be speeders. Again, the best advice is to not blatantly break the law.
