Pros
Everything is relative. You could just as easily wind up in a good group as you might a bad one. Tuition reimbursement is available, benefits are average to slightly above average, and TIAA CREF contributions are generous. If you keep your head down and do as you're told, you could hide here for quite some time. ETS has many employees that have been employed 20+ years, but unfortunately their skill sets are outdated.
Kontras
The educational assessment industry is moving quickly, and I'm not convinced that ETS can keep up. They've already begun to lose College Board work in the digital space and have difficulty delivering anything without significant contributions from companies like Accenture and PwC (see the recent challenges ETS had in assuming the State of Texas Assessment of Academic Readiness from previous vendor Pearson). They struggle to provide competitive pay and therefore lose some of their better talent to jobs in NYC and elsewhere. A focus on people development is lacking. If you are looking for work-life balance, there are several areas you should avoid and IT is first among them.