Casual, both good and bad.

Casual or professional in the workplace, both have pros and cons.
One of the greatest companies to work for allows their employees to wear anything, while it can be said that looking professional will get you farther.

I think the one thing to consider is that if you are working for a company that has a casual dress code is whether or not you have the job of your dreams. If you are looking for a comfortable position then you'll be fine to just drift through the casualness of the office. If you're hoping to be more than get noticed in an environment where everyone is casual and you look professional.