We already had 5 Alen units in our house and have been very happy with their quality and performance. We decided to try this newer Breathe Smart unit. We placed it in our open living and dining room area which is a large area. My husband immediately noticed that this unit was quieter than our other A350 units. I also liked the particle sensor that is monitoring if extra air purification is needed at times. The one area that I would recommend is to create different front panel options/ colors to match with people's decor. Right now it is a very large plain white plastic covering, and it is a fairly large unit so it stands out a bit in our living room.