Pros
Incredibly rewarding work. Flexible work hours and remote work possible (and pretty standard for most positions). Great benefits (employer pays all healthcare premiums, employer contributes a set amount to retirement plans, 3 weeks paid vacation, cell phone reimbursement, 5 weeks paid maternity/paternity leave, professional development, etc.). Salaries, even for entry-level employees, are comparable (if not high) for the non-profit sector. Internships are paid. Increasingly diverse workplace (majority of employees are now women). People at the organization are friendly and generally committed to dealing with problems and issues rather than ignoring them.
Kontras
Rapidly growing organization, and operational and management systems are lagging behind that growth. Different positions and different programs have varying opportunities for career advancement and growth. Non-profit status means programs, positions, and advancement is often contingent on uncertain funding sources.