Pros
Great learning experiences, you can assume leadership responsibilities(note - the responsibilities, not the position!) very quickly, big name clients and really interesting projects. Opportunity to meet a lot of different people not just within the company but also in the client companies. If you are open to travel , it is even better
Cons
No work life balance. Highly political(La office) A number of people I worked with in my team were juniors on a visa who had no idea how to deal with people and were very focused not on doing a good job but avoiding responsibilities for mistakes they made. Leadership especially in the Los Angeles area seems content on getting the job done, instead of weeding out poor performers or encouraging good performers. Being promoted comes down to whether you are on good terms with your manager. I have seen a number of people totally mismanage a team, heard them claiming credit for an issue somebody else in the team fixed (in meetings where that person is not invited), managers not giving out all the info required for the team to do a job and then coming in at the last moment with the missing information and looking like a hero in front of the client etc. If you can play the game in a political environment, then go for it. Most people I know prefer to walk away with their sanity intact, which is what I also did.