I agree with the practice tests. exams4pilots is what I use to get all my students ready. All I have to do is set them up with a test and make sure they get an 85. My student got an 87 on the site and a 90 on the actual written (just a couple of weeks ago), so I would say it's a pretty good barometer for the real test.

I tried using shepard air for my ATP written but found that I could do much better buying an app from dauntless for half the price and just doing practice tests over and over.