I marked something as correct and got a 500 error in a modal dialog box that can't be closed, forcing me to close the whole tab. This is exactly why extended private betas are so damn useless. You can't do a perfect launch no matter how much you fret over trying.
Just because it's not perfect doesn't mean it couldn't be a lot worse. Their site appears to be having load related problems. Closed betas don't provide a lot of load testing.
I suppose it depends what the goal of your private beta is. If they were primarily testing their search results then maybe it was a success. If the goal was to launch and have a polished stable product I think they failed.
