We’ve been running the 14,000 BTU unit for about a month and so far, so good.  It is May in coastal VA, and weather has been mostly mild, but still warm enough at times to definitely have needed it.  We have a 1300 sq ft condo with tall ceilings and large open kitchen, dining, living area, and it has done a good job cooling the entire 700 sq ft area.  Noise level is a bit less than expected, so that’s a plus.  With the high ceiling, the louvre allows us to direct the airflow at the living level, rather than blowing it all up to the ceiling.  
Note that, with this large unit, the compressor turning on does cause lights on the same circuit to dim temporarily and one set of LED lamps flickers continuously, so it needs to be plugged in away from sensitive fixtures to avoid that.
We have not seen the worst of summer yet, so we’ll see how well it does when we get to 95, but as mentioned, so far, so good.