Pros
Beautiful office space that you will be proud to show off; some (not all!) great projects; excellent support staff; ethical management. Most people keep their egos in check. Average benefits. Great social support, especially for younger staff.
Cons
The informal management structure works well for the top ten percent of people running the firm and the bottom 60% who are drawing the drawings. It's a mess for those of us in the middle. Having to report to 3 different people with different goals is a mess; having all the people who report to you also reporting to the same 3 people above you makes for an incredible lack of consistency and reliability. Populous has a "work hard/play hard" philosophy. Which sounds fun, but actually means "work lots of overtime/spend all of your free time with your coworkers." Pay is slightly below average. Better than small boutique firms, but not as good as the big firms in their league. Annual performance reviews and yearly raises are (intentionally?) far apart on the calendar and completely unrelated to each other. The promotions process is badly managed - an employee's direct supervisor is usually not consulted when promotions are considered, so occasionally an employee can go directly from nearly-fired to a promotion. This final one can be a pro or a con, depending on your perspective: Populous is a SPORTS architecture firm. They are the best sports architecture firm in the business, hands down. When you interview, you will probably hear all about convention centers and airports and product design and other great things. They are all true. But they are a tiny, tiny chunk of the business. You will work on sports buildings, and you will probably go for years without touching a non-sports project. Even if you beg to work on a convention center, even if you get totally burned out on sports, you will probably never have an opportunity to work on anything but a sports project. Not everyone who works there is a sports fan, and that's ok - you won't have to fake it or lie about it. But if you're not a fan, you have no potential for career growth at the firm, and you should not expect to be promoted above the level you're hired at.