I've been using cups for a few months now, since november last year. I originally got a femmecup which I've had no major issues with, but I also won a keeper mooncup from a blog (sorry but I don't have the link handy) a while back and I have to say I prefer the mooncup for sure. At the moment I'm using my femme on my heavier day and the small mooncup on my lighter ones, as the capacity is a little less but its more comfotable and easy to use for me. I've often had issues having to fiddle with my femme to get it to pop, whereas the mooncup will pop straight away every time, and always seals perfectly for me. It also has a rounder rim, which makes insertion and removal much easier and less uncomfortable. Both of the cups I have completely trimmed the stem off, as any hint of a stem I find to be quite irritating. This works for me since I'm able to remove them by gripping the thickest part of the base and tipping/wiggling them until the seal breaks, then taking them out. I love that the femme has measuring lines, and the swirly grip bit at the base is pretty. However, the keeper moon cup definitly wins in the comfort and ease section.
I also know about the kinda dodgy-ness of the keeper company, so while I prefer my mooncup to my femme, I will not be buying from them in the future (I figure I won it, so no money from me goes to the company. If anyone else chooses to buy from them I have no issues with that - people are free to do what they want.).
I've learnt some pretty cool stuff about myself (well I think its cool, anyway) since I decided to get a cup. Firstly, I realise now how that half the reason I hated my period was the horrible gross feelinf pads gave me... don't get me wrong, I don't love my period, but I don't feel so bad about it anymore. Consider it scratching one factor off the stress list.
Secondly, my periods are nowhere near as heavy as they seemed (although going off contraceptive pills has probably also affected this. I'm going back on them soon so ill keep measuring and see what happens). I'm actually really lucky, having read some of the experiences that other women have.
Also, as a result of having a cup I know much more about what my body does, what happens to my cervix, what menstrual blood actualy looks like when its not being absorbed. I don't think I'll ever go back to disposables. Not if I get a choice anyway.
I'm going to get another cup, probably a meluna with a ball stem, so we will see how that goes.