I give this an Average rating because of the poorly designed metal sill brackets, where the bolt threads will strip easily, being that they are merely the thickness of the brackets.
Also, the accordion side curtains will eventually deteriorate from the sun, so I applied the foam insulation panels to both the inside and outside.
If you have a narrow window sill that does not extend into the room, you need to extend it with a Redwood 1 3/8" X 1 3/8' or X 3" wide wood to make the sill wider.

Pluses: The unit is very quiet and efficient with it's CEER of 12.0 
User controls are simple to understand.