It doesn't leak at night as pads do, it's cheap and environmentally friendly, but mainly that it doesn't dry out my mucus membranes and doesn't contain bleach and pesticides that I don't want anywhere near my uterus.
The best thing that happened to women in modern times. I could probably even say that it's the best thing that has happened to mankind.
Hip hip hooray! May they improve all menstrual weeks for hundreds of years!