They're actually great, especially when you have no other options. Improvements I made to mine when I lived in San Jose were to seal everything with tape like you said, and insulate the exhaust tube with aluminum foil.

Insulating the exhaust tube dropped the outside temperature of the tube from 130°+ to 80-90°. It also made a noticeable difference in how long my apartment stayed cool.

The biggest problem was dealing with waste water. It's not something I'd considered before buying the unit. Typically, I'd l leave a hose running into a bucket, and empty it every four or six hours, depending on humidity. When I went on long trips, and had to leave my cat at home, I'd do the following.

• Switch out the bucket for a 60 quart plastic storage tub.

• Set up a cheap security camera to watch the water level.

• Set up an infrared remote hub with a temperature sensor, like this one.

• Turn on the air conditioner whenever the temperature in the apartment reached a certain point.

This setup kept my cat cool, and allowed me to visit my mom in another state before she passed.

Didn't quite mean for the story to go on that long. Point is, those standing units do the job.