Pros
HUCTW (Harvard University Clerical and Technical Workers Union) is a literal godsend and is there to advocate on your behalf. I had a nightmare working situation and they were able to advise me through the process of establishing myself in the office and ultimately leaving after the working situation became untenable.
Cons
HR knew that the supervisor I was working under was toxic and had been trying to remedy the situation for almost a decade to no avail. After I left, I think there were some solutions implemented, but the fact that it took almost a decade and countless people pushed out of the office before any substantial change was implemented was ridiculous. Furthermore, the benefits and salary were alright for me as I was a single, fresh out of college person with no dependents (living with roommates, without a car, and with a manageable student debt payment) but I can imagine that the salary is meager for those with dependents (especially living in the Boston area where rent is high). I imagine that salary negotiation is more flexible depending on the individual supervisor, but regardless the salary scale is not very generous for some pay grades.