Pros
You will be surrounded by very bright, capable, and passionate educators and trainers. You will receive fantastic preparation to become an amazing, effective teacher. My mentor was truly wonderful and helpful. I learned so much from her.
Cons
It is indescribably intense; you can't really have anything else going on in your life (like a family or hobbies) because it will consume all of your time just to survive. You are placed as a classroom teacher with no experience (only a summer training course), and you learn "by being thrown into the fire." I ultimately became a wonderful teacher, but I suffered a lot. Extremely intense and busy. You have to attend graduate courses in the evenings, and TFA trainings a lot of Saturdays, in addition to being a brand new classroom teacher. The expectations are extremely high; I was honestly working my hardest and felt like a complete failure when I compared myself to TFA's standards and expectations.