Pros: comfortable, change less often than pad or tampon, ecological, great for travel,
Cons: learning curve, difficult to clean
I love my Diva cup. It works better than anything else and I love that I am not contributing to the landfill and I don't have to wear pads which I always hated (even the cloth ones, although I do like them better).
They are great for travel, small and nothing except the fluid to dispose of in case there is a temperamental toilet or no trash can... those who travel in the developing world will know what I am getting at here. This was huge for me.
The only down side is that it gets discolored--rubbing alcohol helps a bit but it no longer looks pristine. Years ago I got a yeast infection twice using this-- not a bad one, but still who wants that-- since then I clean with rubbing alcohol and boil it, and stretch out where the little holes are and pour water over them while they are stretched out and have had no problems. I have had mine for 5 years and it is still fine, they used to say they had a life of 10 years I think now they say replace every year-- personally i ignore this- although obviously use your own judgement on that.