This has been my experience in northern Pennsylvania with ducted central A/C and ductless mini split systems. Different climates as well as individual preferences vary, so YMMV.
I considered ducted central air when I was building my house in 1979, until an incident in the office where I worked changed my mind. People started getting sick. When it got severe enough, the board of health was called in. They found the inside of the ductwork was covered with a half inch thick layer of green mold. Contractors were called in to clean & replace parts of it. I almost lost my lunch when one of the workers showed me a section of the duct he had removed.
Yeah, I know. Regular cleaning of the ductwork prevents this, but it was just more maintenance which I was trying to avoid. Instead, I skipped the A/C and installed a whole house fan. Since the nights are cool around here, that worked fine for over 30 years. When my wife developed allergies, we had to close the windows at night and use a window A/C unit.
When I retired in 2003, as a retirement present, I bought a Fujitsu mini split system, consisting of 2 compressors with 2 heads on each. The system worked flawlessly with absolutely 0 maintenance for 20 years.
In 2023, to take advantage of a rebate offer from our local power company, we decided to replace the older, less efficient system with a new mini split system which provides both A/C & heat. Our electric bill was reduced by just under 40% and the rebate program paid for half the installation cost.
At the same time, my sister in law began to have trouble with her 15 year-old ducted central air system. At first, it was just a musty smell but then the compressor quit. The cost to replace the compressor and clean the ducts was almost as much as the cost to put in a new mini split system with the rebate program factored in. She liked ours so much, she decided to switch to the mini split.
Now, a year later, she is very happy she switched. Her new system has 2 compressors with a total of 5 heads. She is better able to adjust temps in the various zones than she was with the old central air.
The only down side to mini splits is the heads can be unsightly in some places. The trick it to place them in out of the way locations such as these:
Some complain about noise but I find it barely noticeable. My SIL says, the noise is about the same as her old system.
Even with a mini split, if you have a short line set run to the indoor head generally over the bed (generally 10' or less), it is possible sometimes to hear the refrigerant moving in the line set.
