It is interesting that we are having such different experiences with the Megamax. I purchased a case and have been using MegaMax every night and during some days. My experience continues to be a good one, waking in a very wet diaper - but a dry bed.
I suspect that the fit may be different for us.
I wear 3 diapers, with a booster pad, per day. By the time I change, they are close to their capacity. I should note that, when wearing any super absorbent diaper to near its capacity, I expect it may sag. I always wear a onesie, diaper suspenders, or both to support the diaper. That way the diaper remains well supported and with the internal leak guards and leg gathers in close contact with my body, reducing the risk of a leak.
For those of us who are bowel incontinent, the excellent internal standing leak guards do their job well in keeping fecal material in the main channel of the diaper and away from the leg gathers.
--John
(double incontinent)