According to the crowd at the Reddit thread Valentine one gen 2 vs uniden r7 the Uniden R7 is the Best value radar detector.

The Uniden R7 is a radar detector that is built at the interssection of performance and cost, making it the best bang for your buck. It offers all the latest features and high performance without extraneous bells and whistles that can distract from its primary function of helping you detect radar guns and speed traps. It runs with the top of the pack for detection in testing and is well received by radar detector entusiasts nation wide.