Over the past 7 to 10 years, we have been purchasing this exact model for our house, and all of them still work perfectly. We live in a house that was built in the late 60s, have two cats and two dogs, and three teenagers. I am HIGHLY allergic to cats - if I pet them, I have to wash my hands immediately. The amount of pet dander in my home is outrageous. We also recently had our subfloor replaces in several areas of the house and it has caused a massive amount of wood-colored dust (we need to have our duct work redone and suspect it is a part of the dust issue in the house). These are strategically placed around the house for maximum cleaning.One, these are the best because you can place them against a wall. The downside is that it will create more dust on the wall near the air purifier. Simple logic - the air exits the top and what hasn't been sucked in through the device travels on a path that hits the wall. So you have to dust your wall - no big deal. I have to do that, due to just being noticeable, about twice a year.The hepa filters only need to be changed once a year, and the pre-filter every 3 months. When I change the pre-filter, I normally run a vacuum around the edges where there is dust buildup. This is unavoidable for any air purifier (I have tried many versions and keep coming back to this one).WHAT MAKES THIS THE BEST:- Durability. I have had our first one we ever purchased (maybe 7 to 10 years ago) running all day at the highest speed without going on turbo, consistently and there has been zereo degradation to the unit. It works as well today as it did when we purchased it many years ago.- White Noise. I like white noise, and unless it is on turbo, you don't really think about the sound once you get used to it. My pets are not afraid of it, which means it's just white noise to them as well.- Frequency of filter changes and types of filters. Sure you can buy the name brand filter replacements, but the generic ones are just as good and you save money. Honeywell's products are excellent from my experience, and the device itself has stood the test of time. For the filter replacements, you're just paying for the Honeywell name if you choose their higher priced replacements.-CLEANER AIR! Like I said, we have four of these now. One in my son's room which is a mother-in-law suite - the size is sufficient for the size of his room. The room was an addition built in the late 80s, early 90s, and the door to the outside isn't perfect (old house issues), and some outdoor allergens get into his room. Having one in his room has greatly reduced allergies during high pollen season (we are in the south, pollen is around all year). Since adding the most recent unit, the amount of the brown dust I have seen has been reduced. We also have one in our living room that is large enough to seat 10 people, and a home office. My newest one is located in another home office that I share with my dogs and their crates. Again, allergen reduction was easily noticeable once it was in place. The last one we own in in our bedroom because of my allergies (no pets allowed). I know it has made a difference because I have significantly less allergies in the morning than I did prior to putting one in our bedroom. My entire life has been one allergy attack after another, even after taking allergy shots. These units help me live life - WITH PETS I AM ALLERGIC TO - without a constant runny nose and itchy eyes.If you are looking for a unit that will not die in a year, or start making strange sounds after a few weeks of use, THIS IS THE UNIT YOU HAVE BEEN DREAMING OF! Like I said, we have had the same one for many years (we got our first one at a big box store and I can only guess that it was at least 7 years ago, but I suspect it was closer to 10).