Dave, forget about Radar detectors, they are a waste of space. Speed Cameras use "SLANT RADAR" which means that the radar beam is angled across the roadway and therefore does not travel down its length, making it difficult and expensive to detect. These days handheld speed measuring is done with LIDAR (a LASER-Based speed measuring system). As the LASER Beam is not detectable by RADAR detectors, they are useless. I have also owned a good RADAR detector, but the problem with them nowadays is that they are highly susceptable to false triggering by stray atmospheric microwaves, so to use them effectively requires a fair bit of experience and guesstimation. Spend your money on a good cruise control unit and use it as often as you can. I found this to be the answer for me and have not had an infringement notice for the past 15 years so the results speak for themselves.
David Mc