I never went to ATP but I have two close friends that did. One I started with at Pan Am and left during his instrument (he didn't like the school) and went to ATP. He is now flight instructing in Alaska while I am still not even close to done. Sounds pretty attractive to me!! The other, went to ATP right after he got his private at an FBO and succesfully completed the course in three months and instructs for them. I have never heard bad things about the school. I think the main difference between such flight schools as Pan Am and ATP is that at ATP all of the ground is up to you. Which is not unreasonable, as a matter of fact, I feel like I did that at Pan Am anyways. I just had more time. Of course, you'll probably learn more at a slower pace but if you want your ratings fast, ATP is the way to go. Like somebody else said on this website, "we all take the same checkrides."