We are living in a temporary situation that seems to be unhealthy for me, which was the catalyst for purchasing an Alen air purifier. I believe the FLEX unit we chose is definitely helping with the air quality, as I feel I can breathe better, sleep better, and am not experiencing the physical symptoms to the degree I was before the air cleaner. The results have been very good, but not hugely dramatic. My hopes were that we would also notice a difference in the dust accumulation on furniture, and that the cooked fish odors would be eliminated, but that has not been the case. I'm generally pleased with the FLEX unit, and perhaps a different filter choice for it would be helpful.