There are several thoughts that come to mind about this program. One is, if you go in with your 2 or 3 writtens done and to a high enough score, you will already know a lot about what is required of a new CFI since the only significant extra things for a CFI to do are are sitting on the right side and explaining what they are doing as they do it. As DE says, the rest can't really be taught and you have to learn it on the job ie. the psychology of students and how to best adapt things to hard-heads.
The second thing is AllATPs has a tried and true system of "teaching to the test". They know before you sign up who your examiner is by name, and what he asks for and how much. This really makes a difference in the success rate, however much it may sound like cheating. It's not cheating, they just send a lot of people through the mill and they know what to do to get them ready to pass. So some or all of the speed they offer is just this.
But I think there is also a significant lacking in the ATP program from what I have seen over the years. That whambam memorize a few things and go take your checkride concept does not drill anything very deep into anyone and even less to get them thinking creatively about how to teach. All the ATPers I ever crossed paths with fit this description. The ones that are on their own (ie, not teaching at ATP) are fairly clueless about how to teach. Sorry but it's true to my experience. They are used to being told how to do everything to pass the test which does not involve any creativity. An ideal instructor is good because they know how to adapt the material to the student.
All in all though, since getting started teaching is the main thing to do, I am generally positive about the ATP CFI program. Don't go unprepared, it is best used as a finishing course.