Okay, raise your hand if you
haven't peed down the galley sink when the porta potty was getting full. LOL
Our 550P is not MSD equipped, but I have on more than one occasion disassembled the potty, carried the tank to the stern, and emptied it overboard while we were still three+ miles out. It's MUCH easier than carrying the full tank off the boat, down the step ladder, across the yard, into the house, and emptying it in the toilet (where it splashes all over the bathroom), and then doing all the above in reverse. MUCH easier. Although it does gross out the dolphins.
Still. Looking forward to MSD capability. Very, very much.