Pros
Fantastic benefits. Opportunities for very interesting work, depending on the position. Tons of flexibility to work to your own schedule and style if you are lucky enough to have a flexible location position.
Cons
The working experience at TNTP really depends on the position and direct manager. Work-life balance really varies by position. Some positions basically require employees to sacrifice their personal lives entirely, while others are busy, but manageable. (They tell you in the interview that the average week is at least 50 hours. This is no joke.) The quality of management varies enormously. People seem to promoted to managerial positions on the basis of their ability to meet their goals; actual management skills are evidently expendable. My own managers have been along the spectrum of terrible to pretty good. The culture is intense, and more than a bit arrogant.