Recently purchased an Alen Air BreathSmart air Purifier and I must say I am both surprised and extremely satisfied with the product. Talk about eliminating dust, pet dander, odors and bothersome allergens... The BreathSmart is an awesome machine and I would not hesitate to recommend it to friend or family, in fact, I have done so already. Great smart sensor functions, very quiet, and really useful prefilter (trapping lots of large dust particles and hair) and very simple to clean. I have not yet enrolled in the AlenAir filter replacement plan but will do so when I'm notified by the purifier itself that a new filter will soon be needed.