K9AN (6505km) is, so far, the first USA station to spot my 500mW 10m beacon today. First USA 10m WSPR spot was at 1318z. I am quite surprised that I don't have a log full of USA spots on 10m WSPR from the USA today. So far only K9AN and KK1D (5455km) have spotted me on 10m WSPR from the USA today.
UPDATE 1900z: I have now gone QRT on both 10m and 6m WSPR. I am QRV on 630m WSPR with the homemade transverter running 5mW ERP, listening 80% of the time for others. No RX preamp and using the earth-electrode "antenna". First station received was F6GEX (590km) in IN97 square at -27dB S/N. Next was DH5RAE (995km).