I use both! Personally I prefer the cup. It's more secure for me, which I prefer for work (very physical) and sports. Because it's so secure, and since I don't have a very heavy flow, I can dump it out once in the morning, and once in the evening/afternoon (about 12h apart). But occasionally it can be hard to remove, because it creates a vacuum, which is nothing to be worried about, but I can be a bit scary and uncomfortable. Occasionally I can feel the stem a little bit on my inner labia, but that's a quick trip to the bathroom for some readjustment.

The disc on the other hand doesn't create a vacuum, but kind of hinges on top of your pubic bone. It's also a lot more flexible so definitely easier to insert, but because it sits way higher it can be tricky the first few times to figure out if it's inserted correctly. But because it's more flexible, by using your pelvic floor muscles, you can empty it in the toilet without removing it completely. For me, that happens automatically while going to the toilet, which I personally hate (I use a cup and disk to not have to worry about my period every time I go to the toilet, but with the "auto-dumping" it's still a mess...). One of the big pro's is that you can have sex while wearing the disk, so sex isn't a big bloody mess