Other than that, I personally have no use for heat and cooling in different rooms at the same time. I understand there could be circumstances for others though.
Depending on where you live in the country, size and load of your home, you can have some decent temperature swings in different areas of the house.
I have a 3 story house, one system for each story, no problem.
Where it can become a problem is between levels of floors and opposite ends of the house, particularly with window space and how the house is pointing direction wise.
Up north above New York and south below South Carolina, generally there isn't a problem. The problems generally appear in the spring and fall where temps are moderate and can swing either way in the "mid tier states".
Thing is, with zoning, these types of issues can easily be rectified. However, if you're using a "multi zone ductless mini split system" you can be screwed very easily because even though some systems do allow you to utilize a auto changeover mode, the time between modes can easily take up past 40 minutes to an hour. Zoning with a ducted system you would never have that problem.
However, with a VRF system, you could easily go up to 20 ton on one system with over 30 indoor units, each indoor unit being able to heat or cool at the same time. Believe me, there is a use for that, but again, it comes down to price vs a good old 20 ton package unit sitting on the roof using existing ductwork LOL
