Here are my basic rules on Interview dressing:
1 When in doubt, wear a suit. For all lifes clothing decisions, better to be over, than under dressed 2 Ask a recruiter whats appropriate, if you are dealing with one. 3 Whatever you wear, make sure it looks nice (no stains, ironed, fits well,etc)
How someone is dressed is a very small part of hiring (in the tech world, less so for other professions), but it does speak to attention to detail, and how they see themselves. Given two equally skilled candidates the one who presents themselves best (attire wise) is going to get the nod.