Bought the 8500 BTU version of this air conditioner and it works beautifully.  It's cooling the living room, kitchen and one bedroom of my 3 bedroom house as I type.  And, we're in the middle of a string of 95 degree plus weather here in New England.  It's definitely quieter than the standard window air conditioner.  It is significantly heavier though and was a bit more difficult to install because of the "inside/outside" nature of the unit.   Make sure you measure the width of the inner window sill to the outer wall exactly!  Turned out that I had to take out the screw in spacers because it was too tight when set across the sill to the outside sill and wall.  But, it works fine and keeps me cool when I need it!