A friend of mine is starting a new campaign and intends to use The Window. I've never played with it, but have taken a pretty good look at it. I'm soliciting opinions, though, to see what other people's experiences have been.
Have you played it? How did you like it? How did you not like it? What kind of game did you use it for? How functional was it?
If you haven't played it, but have opinions about it, let me know.