I had a little bit of discomfort on the first day, but I'm assuming that was 80% first-day-period-cramping and only 20% maladjusted-cup-cramping. I knew my flow was light, but I am amazed at how light. I think that I could theoretically only empty the cup once or twice throughout my whole period. I probably won't ever do that, but it's nice to know that I could, haha.
I didn't have any leakage, no trouble making it pop open, and while I'm still a bit slower than the "few seconds" that the DivaCup's instructions say it should take to insert and remove the cup, I got much better at it throughout the past 4 or 5 days.
I can't believe I was ever skeptical or hesitant to try a menstrual cup, and I would definitely recommend it to anyone who is still on the fence about trying one for the first time.