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.
Congratulations to your 3 years and amazing menstrual cups. I have had one for three years and now I bought a new one for myself and donated the other during the double campaign. Great initiative with the possibility to donate, I wish that all women in the world get a chance to discover the freedom it gives to use a cup.
I have only used it during one period so far and I'm sold! Don't need to think about it, so nice to go and do what one wants and to not constantly have to think about if you have tampons with you etc... I love my cup!