I bought the Diva Cup in November of 2010. I really wanted to love it. My sister in law in Italy (she bought a Moon Cup when she was home in England) raved about them. Everyone's been raving about them. I love the concept of zero waste and the hygiene aspect. I am prone to mind-numbing, intense, kill someone for a decent pain-killer cramps. I can't use this thing for too long without having worse than usual cramps. I've stood by tampons over the years, but even they cause cramps within 20 minutes of using them. I've tried it with every cycle since I bought it and about 60% of the time have to remove it and use a pad. I'm sure the cramp issue is my own personal health problem and no reflection on the cup itself, but, for women who get crampy from any pressure on her abdomen or tampons, use this with caution. Also (men, if you're reading this, look away) if you have a bowel movement, you will probably need to re-insert the cup.
I will say that someone needs to design an inserter for women with small hands, because I just cant get it positioned right without a whole lot of contortion and effort. I've heard alot of women with this issue. Aside from all my rants about the product, it handles the heaviest flow with ease, I've only had one leak and that was user error, not the cup. The stem is a bit of a problem because I can feel it and I can't trim it off because I need it to remove the cup!
In all sincerity though, if you're reading these reviews trying to decide for yourself about getting a cup or not, do. I don't regret it, I use mine as much as I can and if I didn't have such horrible cramps, I would use it 100% of the time. It really is a life changer once you master the insert (youtube is a Godsend on that topic, I use the "punch-down" fold) and it's great for the environment as well as your wallet.