BH-
I was an instructor out in LGB for ATP. I worked at three different locations, JAX, LAS, and LGB. I even spent some time in Phoenix. Atp is a great school. I did almost all my flight training there.
Each location is going to be different. It is all based on the flight instructors at that location at the time of your flight training. Lyle is one of the instructors out there now. I was his instructor in LAS for two of his CFI's and his Commercial Single. He flyies better than most that I have flown with and he makes you feel comfortable in the plane. He also has been there for a while and is in no hurry to go elsewhere. So he more than likely isn't going to be leaving half way through your training.
Dually important is personality. The best advise is to go down and talk to the instructors and getting an idea of how that particular location runs and if you think it is best for you.
I personally recommend the 90 day program. It is the same training but the day to day repetition really aids in the retention. But paying the costs and not working at the same time is not an option for all. So we do what we can.
I stand by ATP and their training. All of my instructors are flying for airlines. Some of my students are also starting to get hired by airlines. You can't beat the price nor the results. It is intense, it is alot of self motivational studying, but if you are disciplined, and focused, they will take you where ever you want to go.