Pros
The people working at LinkedIn continue to amaze me with their sheer ambition and intelligence. We are constantly solving difficult problems and developing software that is on the cutting edge of large scale distributed systems (most of that software becomes open source which I also appreciate). I love how much my manager cares that I am always doing something that I am passionate about. Should I ever find myself in a position where I am not happy with what I am doing, it would be a simple matter to switch to another team. Perhaps my favorite part about LinkedIn though, is that I feel completely comfortable leaving work at 5:15, leaving me with plenty of time to work on my own programming projects or personal hobbies. Sure there are some people who work long hours and work on the weekend, but they are not the norm.
Cons
Coming in as a new college grad, I actually had kind of a difficult time finding other people my age to become friends with. The average age of LinkedIn employees tends to be between 30-40, which I do appreciate since I have a lot to learn from them, but I'm not exactly going to go out clubbing with them. Other than that, the only complaint would be the pace of growth--it's hard to establish good processes for developing and deploying code when the people you work with are constantly changing and increasing. Lastly, considering how quickly LinkedIn is growing, their on boarding program leaves a bit to be desired. I only had three days of lectures, largely about things that were actually pretty irrelevant to my job.