answer:If you have septic trenches and can get them checked before you move in (not sure if you can do this or not before you buy) it would be worthwhile. Check the council regs too. Here, I just had to replace our septic trenches and it cost about $4000 and a lot of dealing with councils. Never fun. They were insisting we put in a bio system that would have cost us over $10,000. As it turned out, our plumber knew what he was doing and were able to argue that we should be able to just redo our trenches. If they work though, no difference. Press the button… the water flushes away anything needing to be flushed and we don’t think about it. Only other thing I can think of is I want to put in a pool and we have to think about where we can site it so as not to interfere with the trenches. (hello Mr Blueiznh posting next.