Pros
Wonderful company events for corporate employees (such as cultural heritage day, birthday celebration for Mr. Marriott, etc.). Very polite corporate culture. Corporate facilities were nice, including a good cafeteria. Best structure of any company I've worked for -- each person had very specific roles on the team, meaning there was little confusion about who did what. Lots of internal opportunities for movement. Bethesda location was great and you can easily live on the metro line and go into DC regularly if desired. Overall, I would take the below average pay to work here again because the pros of working for such an established company are great.
Cons
Company pays less than most people prefer. This is only a problem if you want a nice place in Bethesda, but many surrounding cities are cheaper. Some corporate business units can be workaholic. 60 hours a week is the norm on some teams. Some teams do allow working from home, flex time (come early, leave early), and that sort of thing.