Another mooncup fan here but only ever tried it. I have no issues with it now - like someone said, the first few months were a bit messy getting it in properly. I do still find it a bit icky to empty in the loo - you need lots of loo paper! But in the shower is a breeze. I always give mine a soak in milton (as recommended) at the end of each use and put it away disinfected. It does go a bit yellow and the milton gets it back really clean looking! You need to give it a good wash and clean at least once a day and a rinse/wipe out during the day.
I sleep in mine too and only ever had slight spill over when I've had a big sleep in - say maybe 9-10 hours.

