I have a very heavy period and was tired of using tampons because I'm quite sensitive, so I gave the Moon Cup a try. I had to change tampons very often and that make my skin irritated, I thought the cup would allow me not to go to the bathroom so often. Unfortunately, since my flow is so heavy I have to empty the cup frequently too and end up irritated even though it is much softer than harsh tampons. On my worst days I can fill the cup to the brim in just one hour. And having to go to the bathroom every hour is not OK, specially when emptying the cup takes longer than changing a tampon (you have to be relaxed, the more you hurry, the longer it'll take). The days when I don't bleed very much I can manage with pads.
But my negative experience is just because of my awful period, apart from that the cup is very comfortable, I can't feel it when it's inside (well, I feel something "taking space" there, but there is no discomfort at all, and I can move freely). Putting it in and taking it out just requires a bit of practice, I got the hang of it quickly and I didn't find it messy (although you do get your hands dirty). I like that you can sterilize the cup at home, I never trusted tampons completely and cotton seems "dirtier" than silicone. I only experienced leaks when the cup was completely full, but I think it's very effective if you bleed less (or empty it on time).
If your period is not heavy, I think this cup is definitely better for you and the environment than tampons. Maybe give it a try and see for yourself (I really wish I could use it like a normal person and empty it every six hours or so)
Oh, my cup came with a little bag to keep it, but the bag has a pattern of a cobweb and a spider... no no no no, I can't stand spiders, I can't understand why did they choose that pattern, why a spider? >shudders<
