We've been using the Tion Clever for almost a year. This device significantly improves the life of an allergy sufferer. I can breathe easier, sleep better, and it reduces nasal congestion and swelling. I've also noticed that I clean the house less often because there isn't as much dust on the shelves as before.

As spring approaches, I realized that I haven't even changed the filters yet. The indicator is supposed to notify me when it's time, which I consider a plus since it will depend on individual usage. On average, filters should be changed once a year.

The Clever has no smell, which is important to me. For comparison, my friend's expensive purifier from a well-known brand still smells like ozone after a year.

There is a downside, it's quite large. But given the size of the filters, it's understandable. If you want to get rid of allergies, size doesn't matter.