Energy efficiency wasn’t a major factor in my choice; if it was, I would have gone for an evaporative system. This factor only guided my technology choice: i.e. split system inverter. I only had a passing interest in the star rating and I knew refrigerated air conditioning would be expensive to run.
The greater requirement was that they do an excellent job of cooling. I have lived in houses which had older-style reverse-cycle wall-mounted air conditioners, and I have also owned a portable refrigerated air conditioner, and none of them did a remotely acceptable job of cooling a room.
On their lowest temperature settings, the new air conditioners are capable of cooling an area to the point of making it too cold, even on the very hottest day. Therefore, they are more than capable of handling the worst conditions we experience.
In the course of a year, we don’t get many days which warrant switching on an air conditioner. Downstairs areas remain quite comfortable for most of the day during summer. However, the air conditioners mean the house remains extremely comfortable on sweltering summer evenings and nights.