OK, good; by good luck I am already using the M5 which is the future one.
@felmue yes, the help() function helps but its quite a slog to figure things out. For example I've been able to use the 'Lcd' class to print some text to the Atom S3's display; but when I wanted to change the font, it took me quite a while to figure it out.
(In case anyone else is looking for this, the command seems to be
Lcd.setFont(Lcd.FONTS.DejaVu18)
when I incorrectly tried
Lcd.setFont("DejaVu18")
it crashes the device!)