10m FT8 or 630m WSPR?

Some time ago I was about to QSY to 630m WSPR RX from 10m FT8 RX. When I checked the 10m FT8 sub-band was filled with South Americans, so I stayed on 10m. When I checked a few moments ago there were still plenty of South Americans, so I stayed on 10m. Later, I will probably switch to 630m WSPR RX.