I sometimes wind up asleep for 16-20+ hours, unfortunately. I have several medical issues though I'm most affected by severe, often indescribable chronic pain (lower back/Coccyx, non retractable headache 24/7/365 since Jan 18 2004) and eventually a lack of sleep will shut me down and I'll be out for a day or more.
I have been using the Betterdry (Size L) with a Tranquility Super Plus contour booster pad (do NOT unfold the booster pad side to side as that will render the leak guards ineffective. Simply unfold it front to back and it fits perfectly between the very tall leak guards on the Betterdry diapers. Even after 16, 18 or 20+ hours, I RARELY have any leaks. The best part of this combination is that the pricing is reasonable, and made better when bought from LLMedico as I receive the veteran's discount. You also accumulate rewards as you buy which in my case works out to be almost 2 free cases of Betterdry per year.
I admit, the Megamax is even better, ESPECIALLY with a booster pad, but they're not so superior as to justify the high price which is damn near double that of the Betterdry.
I hope this helps those out there who wind up incapacitated like I do. I am thankful that we have products today that realistically will provide leak free protection over a very long period of time. It's also great in that I wind up MISERABLE when I wake up in a cold, wet bed, sometimes physically incapable of getting out of the bed to change & put new reusable underpads down. That is amongst the WORST experiences one can live through... in indescribable pain, incapable of getting out of bed, stuck there to lie in your cold, wet bed!
If anyone has any questions, please feel free to ask. I don't mind paying this information forward.