Frequency Accuracy

I have been increasingly fascinated by the precision and accuracy available in digitally controlled VFOs, like TCXOs, and disciplined oscillators using either Rh or GPS standards. But the lowly Si570 driving my Genesis 30/20 is holding to +/- one or two Hz, and it's pretty good against WWV, once calibrated. Right now, I've set my WSPR frequency to 10.140215, and I'm WSPRing away this evening....and that's precisely where it's being reported by most listening stations. I can even tell when some rigs are off by 10 or 20 Hz! My goodness, times have changed when I can see whether another station is off by a calibration factor of a few Hz. FYI, W3HH, you are dead on as close as I can call it! WJ2V