I'm a happy Yuuki (large) user. I've been using the same cup for several periods with great success. I've had no leaks (no overnight flow overloads, not even residual slobber!). However, this period I've had two leaks, although they were both small. My insertion technique is the same. However, I have noticed that this is one of the most painful periods I have had. I was trying to figure out what could be the cause of my leaking, but do you think I can just write it off as "one of those periods" when it's not going to go completely perfect as it usually does? Does that happen to other people here?
P.S. I still love my Yuuki. :)