I've been using the cup for 18 months now, so you can call me a pro 😉
The cup promised a lot of things. On most, it delivered as promised. It is indeed more environmentally friendly. It's easy to insert and remove once you get the hang of it. It's better for your body than regular tampons, but still lets me go swimming during my periode.
The biggest disappointment for me however, was actually also the reason I bought the cup in the first place. I was seduced by the promise of only having to empty the cup twice a day. You see, my bloodflow is very heavy and I've been forced to change pads every 2-3 hours since puberty. I will drip right through the thickest, toughest pads. I'll even have to wake up at night to swap pads or I'll wake up in a bloody stain on my bed. I was hoping for that to change, but the cup has not delivered on this front. I still have to empty the cup every 3-4 hours. After that the cup is just full and I start to get leaks (as in streams of blood running down my legs). So despite what they advertise, the product is not great for women with unusually heavy blood flow. I will always wear a thin pad combined with the cup, so I've got something in place to catch the initial spills.
So overall, I still use the cup. It's a bit better than the pads I used before. But it's not all I hoped for.