There can be no question that the debate regarding presentation attire is hotting up. The trend is shifting towards more informal clothing, but unfortunately, with the rapid demise of most major languages including English, far too many people interpret “informal” to mean “sloppy”.
The key is in targeting. Who will you be speaking to? What is the nature of their business and what is their culture and corporate dress code? Is your topic light-hearted or serious? Once you have consciously considered these important factors perhaps reflect on this truth: You only have one chance to make a good first impression, and that chance lasts for 5 to 10 seconds.
Now you decide what you’re going to wear, and which outfit will optimise your chances of success. Then check it out in the mirror. If it looks bad, it is bad. If you put yourself in your audience’s shoes (theoretically, of course!), and you think that you’d buy from this person, then you’ve made a good choice.