Pros
Access to library resources, facilities, talent. High quality infrastructure for science, lots of activities on campus. Being affiliated with Yale lends credibility, respect from outsiders. Reasonable benefits package but doesn't totally make up for the poor salary. Although New Haven has its detractors, it is a major population center with plenty of amenities, easy access to big cities in the Northeast.
Cons
Low salary, insular, bureaucratic, egos. Associate Research Scientist (ARS) is an odd category that is technically faculty but looked down up by professors; it is always hard to explain to people both on and off campus what the appointment means. There are relatively few ARS on campus so limited peer group, hard to get moral support in difficult times. Too difficult to move up the non-tenure ranks. Considering experience and skills ARS pay is a bad joke.