We have a large home, so we already had two air purifiers when I ordered these two. Of them, I am most impressed with this one. First, the price is very competitive, especially since we bought two. Second, it is easy to figure out and maintain. Third, they take the initiative to automatically once a year send a replacement filter. Fourth, it combines both HEPA features and ionizing features, with the option of shutting off the ionizer and only using HEPA, advisable if people are in the room. Fifth, when my machine's lights wouldn't stay on after a few weeks -- though the purifier itself worked -- they voluntarily and pleasantly sent a replacement purifier and paid for return postage as well. Sixth, the air in both downstairs rooms has changed from "iffy" and musty to sweet-smelling. I now feel safe having company sleep in my downstairs' rooms! I would highly recommend this purifier to anyone.