Wow, it is almost criminal in how well its predictions match up with the actual grade distributions of classes I've taken. It's not completely accurate, but it's still far better than anything before.
For one thing, it's definitely correct about the courses that give everyone 4.0s, and also about the courses with massive grade deflation. And grade inflation too.
And it pretty consistently predicts which professors are the toughest graders.
I seriously wonder where it gets its data from. It has only been here for a year, but it has data all the way from 2004 (so it can't just be user input). I'm curious - do you think the site's grade distributions are accurate?