I paid for both Sheppard Air and the All ATP one-day crash course (CBT) on site at the test center before taking my ATP written. I bit off on the All ATP one-day course because they had about half the questions to memorize as ShAir--I thought they had more inside knowledge. Plus All ATP is questions/answers only. Well, on the exam there were at least ten questions not on the All ATP review. IMO, stick with Sheppard Air--aside from having nearly every question, they're "system" and gouge will pay huge dividends.