
I'm not sure which is the fastest/slowest, but I have been told twice what I'm having by this method, both times correctly, and my daughter has just had a baby and her midwife told her consistently from about 4 months that she was having a girl, she was right! So yes I definitely think there is something in it. :-D
Although my friend is training to be a midwife and her mentor thinks it is a load of rubbish.