TFA, the best choice after college?

I was familiar with the name of Teach for America, as well as City Year. Both programs, on the surface, are programs that seem to fit my aspirations. I am honestly passionate about inner city/troubled districts. Between coming from a small town with a failing school and spending time volunteering in Columbus City schools, I have a heart for the kids. I want to meet the needs of the students I will one day have in my own class room, and I often think that the educational system needs to be reformed. As for my role in this, I have always thought as my role strictly being to reform the shape of a classroom from within.
Because I am so interested in meeting the needs in "difficult" places, and college does not equip students to be come teachers, TFA and CY have always seemed like the next step after college.
After our guest speaker from TFA (who spoke very well and I believed to be genuine in her answers), I realize that TFA is not an option for me. I am not seeking a stepping stone or a completion of a "good deed." I actually want to make a career out of serving a school with my passion and effort, not give two years of my time. While TFA makes it possible for people to stay in education after 2 years, I feel that the reform that TFA is initiating may not be the reform education needs.
This is separate from TFA completely, but it reminds me of my current impression of the program...I met another student and we discussed our majors. She was something like "education policy" and that excited me because I, too, want to be a teacher. But she quickly addressed this excitement with "Oh, I would never be a teacher, I just think there needs to be a change in the way we do education." It was frustrating for me to realize that this woman may play a crucial part in how I run my classroom one day, yet she will never spend time with students like I will. So my impression of TFA tells me that the program is creating people who are passionate about changing education, but in a more "hands off" approach. Yes, these participants are going to be spending two years in a classroom, but usually to leave for a better paying career or to serve the educational system outside of the classroom (ie: our guest speaker said she most likely will never teach again, but is studying education). Possibly, she will be on the forefront of future changes. But is 2 years in a classroom and a degree enough to provoke proper change?
The TFA representative also mention the constant change and growth that TFA experiences.This blog post http://garyrubinstein.teachforus.org/2011/10/31/why-i-did-tfa-and-why-you-shouldnt/ hits on one man's perspective on TFA and he talks a lot about what the changes and growth have done to make the program worse in addition to some other arguments he has about TFA.