I decided to buy the Alen 75i purifier because I live in an area that becomes inundated with smoke from seasonal wildfires. I didn't realize what a difference it makes even when there is no smoke outside from wildfires. The 75i was fast and easy to set up. It looks sleek (some guests think it's a fancy speaker). It's quiet and it clears the air in my home quickly. Before I got the 75i I could smell what I cooked for dinner for days afterward. Now the smell from previous meals is gone when the dinner ends. Unfortunately air quality in most cities is not getting better and I believe in the long term benefits to breathing clean air. That's why I got the 75i and why I would recommend it to others.