We like the functionality of the cassette toilet on our Northstar Arrow.
Regarding dumping the gray, I never bother with the hose for dumping the gray water, we have a 2 gallon bucket that hangs on the gray tank dump valve, when I think it needs some drained off, just fill the bucket and dump in a privy, toilet etc. We rarely have more than 1 or 2 buckets per day... Countless day parks etc for dumping...
This set up keeps us out of those dirty dump stations, waste freedom...
The cassette can be filled from any water source, brook, stream etc using the same bucket...
We also have a large filling hole in the top of the fresh water tank so we do not have to fill from a hose source, just use gallon jugs or our clean water bucket..
I would carefully check all the caulking on the camper for cracking etc, especially the roof mounted equipment..
Perhaps some written guarantee from that dealer that they will fix any leaking problems for a period of time, they must be super anxious to move that unit..with winter fast approaching...
Is the roof TPO or EPDM, our Northstar is TPO....