Pros
There is a genuine focus on fairness to the test-takers and research to provide evidence to support practices that are adopted. As far as the work - it's interesting, collegues are very diverse, and there is some flexibility. This can vary wideley based on who your manager is and what level job you have. As you can imagine, more autonomy and flexibility with higher-level and longer service as you build trust. Benefits are good - vacation time starts at 3 weeks for full time employees, plus 7 days of Paid Time Off - can be used for sick or other obligations (or together with vacation time). Health insurance options are generous. Corporate culture of charitable giving. Overall it's a great place to work. I haven't take advantage of it yet, but you can apply for tuition reimbursement to seek an MBA or advanced degree on the side. . . .
Cons
Can have intense projects, deadlines, and expectations, but in my experience, efforts are rewarded. (Watch out on Glassdoor - many of the critical reviews are posted by part-time readers/scorers who work from home - and that pay has not changed much in years as it's frequently determined by clients and contracts. Unfortunately, if a client can get the scoring done by a competitor who promises lower cost, ETS has to be competitive.)