Pros
Fantastic benefits and perks, free courses, paid time off on all major US holidays (depending on your job responsibility, excellent training, enormous resources available to all such as the libraries, athletic facilities, museums. The students and staff are amazing. There are so many fulfilling opportunities for anyone regardless of their rank or affiliation. It's all there, whether you're a Dean. a staff assistant, or custodial staff.
Cons
Politics. Complaints or about higher level managers tend to fall on dead ears. While it may seem that your voice is heard, very little if anything changes. This is not necessarily always true, of course, but there does seem to be some level of immunity at the exempt level. An institution like Harvard can be set in its ways to the extent that it's more comfortable to let things be rather than rock the boat. Harvard needs to provide its employees with better merit based rewards. The Union increases are ok, but they don't recognize excellence since everyone gets them. Merit based raises and job reclassification do exist, however it seems that most managers are hesitant to initiate the process for all sorts of reasons. Pay could be better, but when you factor in all the PTO, insurance options, and everything else, it's hard to complain.