I had a Keeper as a young adult, and then switched to a Diva when my Keeper got accidentally left behind on vacation. I loved it for years, but since my twins were born, I just can't get a good fit (yes, I have the larger size). Everybody says, "kegels, kegels," but I didn't have a vaginal childbirth with the twins, so I'm not sure that's it. Anyway, they're 3 1/2 now, and the thing still leaks, so I've gone back to using washable pads, and tampons for times when the pads aren't practical.
Even when mine fit well, I used to have to remove it to have a BM, and then put it back, because pushing for the BM would dislodge it and make it leak. And if I let my bladder get VERY full, it would also dislodge it, and I'd have to adjust it.