Yes. Silly people think you're non technical, but they get over it pretty quickly (I spent four years of my life walking into rooms of people twice my age to tell them about Linux, I'm used to having to prove my merit). Managerial folks think you're somehow different to your colleagues, and if you're congruent with it - ie, you let your ideas be known when most of your colleagues would rather have a quiet grumble, and say no when you mean it, they'll respect you more often. I've had a continual stream of project managers recommending me for architecture jobs to my superiors, asking for me for other projects, and a whole bunch of beer couriered to me as a work expense.
It's not how you dress that makes you, but how you are. Dressing well, however, is a good way to show people that - provided you back it up with something real.
You stand out, will be socially tested by your peers for doing so, and will hopefully withstand these tests, and gain social value.
Your ideas will also be noticed more, simply because you are noticed more.