I've been playing with it since my invite on Tuesday, but I find it to be quite slow.
I like a lot about the site, especially the filters and being able to see how the number of connections affects the price. The look at other airports within xxx miles is pretty nice, too.
But it signals the end of civilization as we know it:
http://dailynews.yahoo.com/h/zd/2001...to_soar_1.html