They are quite slow compared to other airlines in crediting miles. IME AI for example is much faster in crediting miles when you fly with them - I get a SMS on landing that my miles for that flight have been credited and usually 1 day later for flights I take on UA etc.

SQ takes about 2-3 days to credit miles flying their own metal and about 5 days to credit *A partner miles. I'm still waiting credit of miles I took on a VX flight last Sunday.

Also, SQ and other airlines do a much better job of posting partner airline miles vs. non-airline partner miles.