We kept our tests simple, measuring front and rear detection distance and how well each sensed radar around a corner. Radenso, a relative newcomer, has garnered a strong following with its top model, the $450 Pro M.

For a steeper $650, the Escort Max 360c is loaded with features, including directional arrows and a GPS antenna. ­Valentine's V1 Gen2 is the first major redesign since the V1 debuted in 1992, and at $599, it's cheaper than the original when accounting for inflation.

We couldn't test them all, but we managed to gather three heavy hitters for this test.