I have used the VeSync Core 400S Smart True Hepa Air Purifier for a few weeks now. And I can say it has helped the air quality in my home. I have severe allergies and they are worse at certain times of the year. Fall being one of the worse times, this air purifier seems to be making a difference in my symptoms this fall. I will continue using the VeSync Air Purifier for a good while I think. It helps !