A stylish presentation is an important part of an impeccable brand. Your style say's who you are and how you apply yourself. If you're sloppy or give the appearance that you don't care, then it will be difficult to get people to take your serious.
On the flip-side its important to look appropriate for your environment. People need to identify with you, so be the best in the room and the best for the room. It will pay off in attaining and maintaining great business relationships.