The V1 has an edge on K band in terms of raw sensitivity. So a V1 will always outperform virtually every other windshield radar detector when tested in the lab against a slowly increasing steady radar signal. Yet Bel/Escort hold a few unique patents for detecting true radar signals buried in the electronic noise floor within the signal detection circuitry. This is why, in the real world, a radar detector with less "raw" sensitivity can perform as well or even slightly better compared to another radar detector which has superior "raw" sensitivity.
Another thing about the M4 antenna design used in all of the current Vectors, RX65, 8500 X50, and windshield mount 9500 series. The M4 antenna is fairly well optimized for on-axis radar detection, but has a fairly rapid roll-off in sensitivity more than 20 degrees off-axis. This works out rather well for most real world driving since this optimization gives the M4 antenna good "reach" for relatively on-axis detection yet reduces off-axis false alerts while driving around town or in cities.
But yeah, the RX65 performs splendidly in the real world for highway driving. The RX65, as well as all of the other Bel/Escort products which I supervised the testing of at SML 2008, all detected every X, K and Ka band radar gun shot at them from 10 miles during the final day's straight-line long distance test. That test included 33.8, 34.7 and 35.5 Ka radar guns even though SML published test results only for 34.7 Ka.