It cools your room! Really!
It's not quiet though, it really needs a vibration mat underneath (I'm using one of them beanbag food trays to good effect).
I only have awning style windows in my house, so I had to fabricate a large carboard sheet with hole cut out for the exhaust tube.
I tried one of the material things with velcro stuck to the frame but they aren't reliable and are a massive chore to use.