First of all, let me say that the Overstock service has been excellent. I ordered my Therapure on Tuesday and it arrived on Friday!!I've only had this, then, for 2 days, and already I've noticed a couple things...1) On its low setting, the tower is silent. On medium or high, the fan is engaged and sounds, well, like a fan.2) Personally, I'm not keen on the blue light on top to indicate when the UV lamp is on... I think it's a little too bright.3) Even though it's a "HEPA-like" filter, it still appears to do a decent job with all the allergens and dust and everything else. It is not a true HEPA filter, so just be careful if that's what you need.4) True to form, it does clear out funky odors around the house. I've set it up in the kitchen (that's where I opened it up, and where I've a convenient outlet to test things, and not only does it eliminate the normal kitchen odors, but also the odors from the litter box.One observation I've made. For the last 6 months or more, about every other day, my cat would leave little "presents" around the house for me to clean up -- usually by the front or back door. I do keep the litter box clean, but still he just drops where he wants and poops. We just assumed it's because he's 15yo, and just likes going there. Since Friday, there have been no special presents... he's using the litter box exclusively. Again, it's only been a few days, but it really made me wonder if my cat just didn't like the smell of the litter... If that's the case, then I'm buying more of these for every room in the house!Finally, I made sure to purchase the extended warranty. Most air purifiers we've purchased have lasted only until the manufacturer's warranty expired, so I feel extremely comforted that Overstock.com will take care of me should this device fail to stand the test of time.Thank you, Overstock.com!