1) ATP: With the course only being two weeks long, ATP looked like a good idea, even if the price was about $2000 more then American Flyers, plus you get an MEI with ATP. But after hearing some bad things about ATP here, I decided not to go there. Someone in my American Flyers CFI class started at ATP and said it was brutal. ATP teaches you just enough to pass the checkride, that's it. You don't learn how to teach material from what I've heard.
Only go to ATP IF you are ready to pass the checkride before enrolling. After covering the material I did at AF in a month just for CFI and CFII, I couldn't THINK about covering it in 2 weeks AND be ready for a checkride.
If you've got limited time, are really proficient in all your flying ( incl commerical maneuvers, instrument flight and you have a multi rating) ATP could be for you.
2: Local FBO/ Part 141 Community College Course: I have received all of my current flight training this way, I started the commercial Part 141 but finished it a couple years later Part 61. If you have a community college near you and near an airport, see if they have a program. The State of PA gives a discount to flight training done at the college or community college level to its residents, although they have changed the rules a little bit. And I enrolled for the summer session for CFI classes at the community college, but with two weeks until classes began, I was the only one enrolled, meaning the college would cancel the course.
But the reason I didn't go this way was it would be the same school I've been dealing with. And the problem is that they are phasing out their C-152 airplanes and haven't begun replacing them with anything else. So this leaves the 5 Skyhawks and a Diamond DA-20 (two-seat Diamond) for primary and advanced training, and a sole 182RG for complex/ high-perfomance training. In other words, not enough planes to go around.
With the 182RG at $145/hr. plus instructor, tax and fuel surcharge, it was going to cost me nearly the same to stay home and become just a CFI. Or I could go to American Flyers and get a CFI and CFII.
3: Other "academy" schools. Too expensive and too many mixed reviews.
I felt AF was worth the money and time, but not everyone can take a month off of work. They will work the program around your needs, but it will take longer and cost much more. Find an American Flyers with a CFI Academy, don't do "one on one" courses, they are rather expensive for Part 61 in my opinion.