Received my 6400M yesterday about 2:00 EDT. Had all the cables ready so it was up and running in about 10 minutes. I was expecting the learning curve to be fairly long but the people who designed the software made it very easy. Talked to several people that know my voice and were very complimentary of the audio. I didn't do anything to the audio but select the mic profile. I am blown away by the noise mitigation. Generally the radio is much more than I had hope for. Great job Flex.