As you may recall I ran some 500uW WSPR tests this Es season, but was expecting better results. When Es is good signals can be strong so I was expecting plenty of spots.At 10mW I had few issues whereas at 500uW just a few spots. Maybe at this power I was below the local noise floor? Also, there may be fewer monitors on 10m WSPR these days as FT8 is a QSO mode.
Overall a worthwhile experiment even if the results were unexpected.