We had a Haier 8000 BTU that was pretty weak. And then the control panel burned out after two years of purchase. So I bought the Costway 8000 BTU. The Costway cools the room much better than the Haier (they actually look very similar, so I didn't think there would be much difference). One downside is that it makes a slight high-pitched vacuum sound while it's cooling. Hopefully we'll get used to it. 

I see people complaining about their new portable ACs not working: always be sure to let it sit upright 24 hours before using it, so the components and oil can settle back down after being delivered or on its side.