I got my CFII through American Flyers. It was a good program and I was well prepared for the check ride. I had the opportunity to use the Frasca 141 FTD frequently and got a fair amount of practice that way. I have no complaints about the training. I taught there part-time (ADS), then full time (ADS & FTW) about two years later.
The financial part is a different story. I paid up front and flew against that amount for eight weeks. At the end of training, with my CFII temporary certificate in hand, American Flyers owed me over $700 of the amount I paid them up front. It took several concerted efforts to get that money back.
If you have the money to pay up front...don't! Put it in a seperate checking account (interest bearing if you can find one!), then pay as you go. Any interest paid goes to you, not American Flyers.
If you are planning to fly at FTW, beware of Billy Fulton. He'll make things sound much, much better than they really are. He's a consumate used car salesman, and one of the biggest bufoons I've ever known.
I got my CFI/I there a number of years ago and then worked for them for about a year. I think I paid somewhere in the neighborhood of $2000 for both ratings (excluding checkrides), which was a fabulous deal. I felt 100% ready for my checkrides.
On the other hand, its ALOT of self work. The class was from 8am til noon, and it was 1 student teaching the others. The students trade off teaching lessons. No student teaches all the lessons, so be prepared to not be prepared...if you know what I mean. I think the best way to do it is to get into a small class (3-4 people at the most) so that you don't sit there for the whole month and only present 1 lesson plan. You've GOT to be motivated to get through the course.
The other post was dead on about the "car salesman" attitude. All of the managers (with some great exceptions - I know some great folks there) will pump up everything about flyers....and then not produce. Talk to the instructors. They'll give you the straight skinny. And don't give them money. Make them work to get it from you, not the other way around. Pay as you go.