I see the practicality of the helmet mirror but only if I lose my peripheral vision or lose the ability to move my neck but to each his own, in the end we should use what makes riding more comfortable and worry less about how we look while doing it. One guy I sometimes commute into the city with would fit the Fred description perfectly since he rides a mountain bike with panniers, wears a helmet mirror, has a million lights, and a really loud whistle to alert cars of his presence when needed. Some of the guys on expensive bikes who don't like getting passed by a guy on a mountain bike quickly learn the hard way that it's 10% about the bike and 90% the rider as they get dropped like a bad habit. He's a really strong rider and races for Strictly Bicycles so it's nice when I run into him because he constantly turns up my commute/training ride, when he says "boy you really made me work on that hill" it's a great compliment. The moral of the story is to not judge a book by it's cover, but you already know that.