What do you look for when you are seeing new software on the web?
Me, I read what it does, and then I take a look at a screen shot (if available, and it'd better be). A polished UI doesn't neccecarily means a polished application, but it helps :-)
It's much nicer to work on a good looking interface than on plain one, and the amount of work invested on the UI is usually 100% user-visible, while that bug that happen only on 2:00AM every third wendsday usually isn't.
1 For such a snappy UI, it sure has a plain web page :-)