Pros
The benefits are awesome, quite liberal with sick leave and PTO, and generous holidays. A beautiful campus (Ashburn) obviously showcasing HHMI's endowment fund, great work life for the main scientists, and free coffee/tea with subsidized food.
Cons
People are clique-y and gossipy perhaps due to the terrible communications and lack of transparency, even within a single project meant to be working together. As others have mentioned, the right hand doesn't know what the left hand is doing and people are often very secretive even with information needed collaboratively. The company obviously sucks up to visiting scientists and bigwigs to save face, but they will turn on you in an instant and kick you to the curb --regardless of your contributions to the company. Heaven forbid you are anyone without a PhD, who are treated lower than dirt. There's almost a draconian form of management and they have lost many a great talent and minds because they refuse to address what makes employees unhappy; morale is low campus-wide and management is in a constant state of denial. There is almost always a constant power struggle at every level, such that work can't be done without people bickering. Actual teamwork is rare. There isn't any room for growth; it is almost as if they purposely keep you down and out of the loop so that you can't command more recognition. A person could be denied a promotion or a better opening because they could use you at that lower position with lower pay. If you were such a valuable asset, why not treat you as such so you won't leave? Even if you put in long hours, contribute so much to a project, it is doubtful to get any recognition; deadlines can be missed and key members can be lost just because personal conflicts can't be resolved. Their reasoning for salaries/titles are ridiculous and not merit-based; if you can bear it long enough, you will get rewarded in the long run by time alone, not effort, hard work, or contributions. Little incentive to be loyal to a leader that is not loyal to its employees. When being surrounded by luxury and money being thrown around, denials due to budget restrictions and menial salaries seem at odds with the company values.