Pros
Good office space in a convenient location in the loop. Trains to the suburbs are just a few blocks away. There's often food from meetings to grab in the kitchen. There are still lots of smart people around to learn from. Work hours are flexible.
Cons
The office culture was driven but casual when I joined. Since then, the company got larger, and senior management has forgotten what made the company successful. It's getting harder to get promoted, which is terrible for the young people who join us. And since we're getting bigger, the only way to make a big difference is to get "cherry-picked" into a cutting-edge project. The pace is still aggressive, but perks are disappearing every week it seems. Pay is average for the industry, but bonuses are getting smaller. Even worse, they (and raises) are mostly determined by how popular you are with your manager and managers from other departments. Finally, executives and senior management keep making big promises about positive new things, but they rarely deliver, and they've stopped listening to the complaints.