Be prepared to be challenged, pushed and work v hard
Pros
Amazing benefits, travel, food (which is phenomenal), opportunities - placements, working on different projects across the company, being constantly challenged, needing to think - constructively, properly and sometimes really quickly, amazing colleagues who are similarly extremely smart, fast and challenging
Cons
You need to be prepared to work hard - your bonus, standing, salary etc are all predicated on you working hard and continuing to improve. You need to show you are a team player as well as an individual, so be prepared to take on extra work to make the grade. It's a large company, so you have to find ways to stand out. Don't expect much of a home life at times - when you're up against it, it's expected you'll stay there all hours.