I would like to share my experience with the Oreck XL Professional Air Purifier that I have been using for the past 3 months. First of all, this is the first home air purifier that I have used, so I don't have any comparision point of reference.
This air purifier looks really nice in silver, almost like a printer or fax machine and blends in with my home offer decor very nicely. I also like the fact that the silver model was a bit cheaper then the one in black.
On the lowest setting it is very quiet and you can have it on no problem while watching a movie in the next room. If you want quicker air purification, you can crank it up which is very loud (does not affect air cleaning quality)
I like the fact that no bags are required to maintain this machine, and that you can simply wash the filter out every month or so to keep it clean and functioning in tip top shape.
This is a solid choice to consider if you value what you breathe in and have a moderate living space to maintain.