It seems like muscle tone is a factor when you're choosing a cup? I'm under the impression that women with poor muscle tone do better with a stiff cup, right? Does the opposite hold true? That women with great muscle tone should use a soft cup? I don't know... I've read that women with great muscle tone can "crush" soft cups? Ugh, I feel confused. My own muscle tone is average-ish (slightly on the poor side, not very far from average though) and I wanna know what's up. I currently have the Si-bell cup which is very soft, will I need a stiffer cup or will it likely be fine if I improve my muscle tone?