E.S.
One big problem with sippies (as I see it) is the issue of how much suction a kid has to use to get the liquid out. Having to suck really hard can contribute to ear infections. But, more "loose/leaky" cups often don't require as much suction...therefore, less risk. I experienced this with Born Free. I just used non-sticky stuff like water or herbal tea..so the mess was not an issue.