Does the job well The HAP750 works as advertised, though it is a little pricey. I used to feel stressed about food odors permeating into the clothes I wore - because my roomate does heavy indian cooking in the house. The hap750 has cured my worries in that regard. Now, I can't smell absolutely any odors in my clothes or in the room! And the air feels light, kind of like when the sky clears after a thunderstorm. My guess is that it's due to the HEPA filter. A pretty blissful experience to have in your room..
The fan noise is very low for an air purifier (it sounds basically like wind blowing at 15-20mph on an avg day). It is definitely much lower than that of the conventional fans. Noise was my major concern because I love silence, but I can live with this little noise.
My only concern is that it requires 3 activated carbon filters (cheap) and 3 HEPA filters (expensive). For now, I feel that the cost is justified for the job that it's doing....more info