here's the straight up recommendations on radar detectors.
1 on the interstate a handheld CB is your best bet, by far. Ask a trucker a mile ahead and you know.
2. Bel, Val, passport 8500 are good.
other than that, you get what you pay for. Cops have YEARS of experience. They know what you know about avoiding tickets and know how to fuck you. They win in the end.