I bought this for a small apartment for several reasons.  One was that I did not want to bother installing and removing heavy window units each Spring and Autumn.  Second was that I didn't have sufficient storage to handle the units in cooler months.  Third was that I wanted the flexibility to open windows when there wasn't a pressing need for air-conditioning.
The LG portable works very well.  It cools the living room during the day, and then moved into the bedroom at night.  It's easily as quiet as the window units I had, and probably quieter.  The casters work well making it easy to move from room to room.  It's a breeze to install the window mounting.  My only criticisms are: would have liked a longer power cord; haven't needed to drain it, but it looks a bit clumsy since the drain tube is so low to the floor.  Although it's not inexpensive I am very satisfied with the purchase and would do it again.