Earlier quoted context omitted.
We have four in our house and they are workhorses. Still running strong and quiet 3-4 years later of running 24/7. Probably one of the best things I've ever bought. They are also popular enough, and have been around long enough, that there is an "ecosystem" of third party replacement filters that are affordable and capable. The sound of the Coway is also quite nice for sleeping in our opinion. It's a quiet "whoooosh"…
What benefits do you feel from having four filters? Not hating, genuinely curious. It's just never occurred to me to filter the air in my home aside from burning something on the stove or similar
Especially in autumn when the wildfires start up - even if it's many miles away there is a very noticeable degradation in air quality.