This particular air purifier puts me in a particular spot. It does exactly what it's supposed to of purifying the air in a given room, making it clean and safe to breathe. It's very quiet, about as quiet as a given central cooling system, or a tower fan on a low setting. The night light feature is nifty for dark rooms but without being blinding, and it uses little power for what it does. Simply put, it's a fine air filter and there's nothing wrong with the air filter itself.
The problem with the device is largely an external one - the price of the filter replacements are nearly as much as the device itself. The filters cannot be simply cleaned or rinsed off, and must be outright replaced every 2000 hours. This sounds like a long time, but for a device meant to be on at all times, will equate to a little under 3 months. That cost can quickly pile up as simply changing the filters twice will cost more than the machine itself!
If the cost of replacing the filters do not concern you, then by all means go for this one. If cost concerns you more, look elsewhere for air purifiers that have more cost effective filters.