Quieter then my older unit, was actually worried it would not cool off my unit well (about 450 Sq Ft). since it is not rated for this size of space.  That being said after a few days of 90+ degrees and high humidity, it cools it off better then my older and much louder unit (53-55 decibels on the older unit).  Also, not bad looking at all.  Only small knock, it seems almost impossible to find.  Friends have looked for this unit and found its sold out frequently everywhere.  It gets very quiet in operation once your desired temp is reached.  My air purifier is louder then this unit at times.