Well here is the last bit that I know...
2 story, 2300 SQ foot house in Colorado
The duct work is 'professionally engineered' with hi/low returns in the master bedroom, the study area upstairs, a central hi/low return in the center hallway, and hallway to bedroom cross ventilation.
Downstairs there are two hi/low returns one in the 'great room' and one in the flex room/5th bedroom.
Upgrade options are... NO HEAT PUMP.
Lenox is the unit of choice.
2.5t 13ACX paired with the ML193
2.5t XC17 Single Stage paired with the ML193
1.5/3t XC21 two staged paired with the SLP98V variable capacity gas