First off, this air puffier works and is very easy to operate. It is lightweight, has a nice lite digital screen (with options to adjust) and it’s quiet. However, it does have some issues with getting this device to work properly.🆇 Issue 1: Not picking up obvious odorsI placed my $600 Alen Purifier right next to this machine and immediately at the smell of odors this machine will NOT be triggered to turn up. The air quality meter may increase some (1-5 points) but never enough to be triggered to automatically turn up past low (unless I manually did it myself). Meanwhile, my other puffier will turn on before I can smell the odor while this device is still unbothered/not recognizing the odors to clean.🆇 Issue 2: Wind drifts matterThis device seems to ONLY be triggered if you fan or blow something directly into it. So if I shake a sheet in its direction and/or spray a freshener in its vicinity, it will then turn up to clean the air. This is an issue because ideally, you want it to clean the air without having to prompt it to do so. For example, I could smell cigarette smoke from my neighbors (or nasty food odors) and my other purifier immediately turns up while this one stays idle. This is not efficient. My other purifier automatically turns on without needing to have the "right" breeze to trigger it.TWO MONTH OBSERVATIONAfter using this device for TWO months, I can conclude that this device does work but not properly (or efficiently) as my other device. I wasn’t expecting it to operate like a $600 purify but I expected it to work similarly at a smaller capacity (at 463 ft max). This did not. If you have constant air circulation blowing at this device you may get a better clean but this isn’t convenient for me. It’s easy to operate although it’s not fully functional at all times. Unfortunately, I can not rely on this device alone so I had to give it 3-stars (although I would give it 2.5 if I could). It's better than others I've tried in the past at under $150 but it's just better than the worst.