I used to use a Mooncup, the bigger size. At the time it was the main brand on the market. It worked great for me, and I rarely ever had to empty it at work (I kept a bag of wipes, etc, which made it all easier). Yet it still held loads as my periods could be really heavy.
I did cut pretty much most of the stem off. While I couldn't feel the cup itself, I certainly felt the stem and it was uncomfortable. I had it cracked during the first period I used it. Probably more luck than anything.
I'm coming out the other side of the menopause process now, no periods in nearly two years. As I had heavy periods for years, and pads and tampons would irritate, I really wish I'd known about mooncups as soon as they first hit the market.
DD is moving to reusable pads. She doesn't like anything internal. We're looking into recommedations for pads for heavy flow. It's getting difficult to find disposable pads that don't have scent or "odour control" chemicals in them, these cause her skin to feel sore and irritated. (Was the same for me, on the rare occasion I was caught short without my cup.)
I might have trouble using a cup now, though. While I don't have a prolapse, I do have a weakness in the area (yes, I'm doing my kegals....).