Before making any decisions regarding air conditioning, we spent months and months....and months doing research. I even consulted for months with a group of environmental PHd scientist/engineers. Their recommendation was Daikin inverter split system. It was the highest rated SEER 19.6, efficient, SUPER quiet system they recommended. It is a ducted system because I didn't want units hanging on the wall. We had metal ductwork installed and had it insulated. Our ceilings in the great room are 20 ft. tall with no attic above, so we had the the grills in there installed high up on the side walls, which works great. In the master bedroom, we had the cassette type installed in the ceiling. It has little louver/fins on it that you can set to move up and down to distribute air flow. It has a separate thermostat from the other, so we can run it or turn it off. The thermostats in the great room and rest of the house are by remote control, but if we wanted we could have an in-wall type thermostat as well. We are extremely impressed with this system. You cannot hear it running at all. If you want more info, I can send it to you.