Not sure why these folks take the time to perform useless distance tests when in the real world we don't all drive in the desert on straight roads with no interference. To test a radar detector it needs to be tested in the real world with hills and curves and every day interference from nearby automatic door openers etc. Based on these distance tests that speed zones did, one would think that a $200 Cobra radar detector would offer the same performance as a $500 Escort Redline since they both can detect at 9 miles away.
In the real world you will never see a 9+ miles alert and police don't always drive with their radar units constantly on. They are sneaky and hide behind hills and curves and use instant on, more so than constant on. I hope anyone reading their review realizes that there is more to a radar detector than picking up at a distance on a deserted straight road.
We stand by our 2013 Radar Detector Reviews and for 2013 none of the new units from Cobra or Whistler compare to the higher end units from Beltronics and Escort.