I just read the results of the ARRL November FMT. I used my "new for me" Flex 6700 and got within 0.04 Hertz of the official frequency on the two transmissions that I could receive. The GPS disciplined oscillator gets most of the credit, however, FLDigi's Freq Analysis mode + using two other slice receivers to monitor WWV on 2.5 MHz and 5 MHz to get an estimate of the Doppler shift (in Spectrum Lab) made the difference. This rig is a technical "tour de force". Thanks to the engineers and software developers that made it possible.