I've had this for over 2 years now and am still very pleased with it. The unit is going strong and working as well as when I first got it. I clean it every 1-2 weeks and replace the hepa filter as needed. I'm still happy with my purchase and will update this review if anything changes.I did a fair amount of research before buying and was hopeful that I had made a good choice. I'm happy to report that it is working very well with very few problems.I bought it to use in my bedroom, as I've been using it as my "smoking room". I'm trying to keep the rest of the house smoke free so I've blocked off my air return to the furnace and run this unit constantly. It is doing a good job of cleaning the smoke from my room. When I'm out of the room for a few hours, I come back and there is no lingering smoke smell. I've asked non-smokers their opinion and they agree my room is not reeking of smoke after using it.The only negative is that after 6-9 months, the display get strange and turns black, so it is very hard now to read the symbols. I discovered that this only happens when I run the ozone function and once I turn that off, the display clears up within and hour or two.On days I am not actively smoking in my room, I turn the purify function up to 2 or 3, and leave the door open and it helps to clear the cooking smells from the rest of my home. (about 1300 sq. ft.)I clean the unit regularly as per the instructions and it works great. Now it is time for me to replace the HEPA filter so I'm hoping that is not hard to find. Overall it has turned out to be a very good choice for me.