Pros
Great benefits package. 15 vacation days + 3 personal days (18 total) to start! After 5 years of service, earn 20 vacation days, plus personal days, per year. Great discounts on Harvard courses - take Harvard Extension School courses for $40 each (currently) - up to two per semester (spring, fall, and summer). I don't know what will happen in this economy, but there have been up until summer 2009 great yearly pay raises (4 to 5 %) - negotiated by the Harvard Clerical and Technical Workers Union. A lot of professional career-development and skills-development trainings and workshops. An environmentally friendly environment.
Cons
For some, the salary may not be as high as could be earned elsewhere. Harvard, surprisingly, will not give free tuition to the children of its employees!