Pros
Really determined, goal-oriented, generally friendly, and high-performing employees make for an overall good organization. Lots of teacher-heads ensure that the overall conversation and direction at each site skews towards instruction and, when dealing with things like district structure/systems, TNTPers stay focused on what needs to happen to strengthen teaching and improve learning outcomes.
Cons
Several reviews here on glassdoor talk about management at TNTP being hit or miss. I think that's exactly right. If you are considering a job with TNTP, absolutely ask about your manager and activate your network to learn more about this individual. I got a chance to work with a number of outstanding people at TNTP, and heard about other peoples' managers making them more effective. That was not my experience. I like to think I am generally pretty amiable and I am used to hard core urgency in other intense ed-reform organizations... and I found my manager so abrasive, condescending, and such a micromanager that it led to a sort of paralysis, and I quit. My manager had been a manager for a couple of years at TNTP when I started - I don't know if micromanagement had led to success with other employees or if this was something she wanted to try out with me. Some of my favorite quotes that she often repeated to me: "the best way to establish authority as a new manager, is to tell people what to do"; "you need to stop saying 'thank you,' it's their job - you're their boss"; and, anytime I completed a menial task, "I think this is SO SMART of you." I found this all to be somewhere between annoying and offensive, so I left.
