I have been doing research on heat pumps for my purchase this Feb. So far the sellers or Goodma products praise them while the other sellers say they require more service. Janitrol and Amana are Goodman products. These units sellfor less than Trane, York and Lennox which are the most reliable and most expensive. If you live where temp in summer is higher than 100 deg. the Lennox and Tappan are the most efficient units at 115 deg. Tempstar is in the middle range.
The difference between low cost units and higher cost units range from 1200 to 2400 dollars. Get at least a 12 seer unit if you have 100 deg. temp
Good luck on your choice.