The only "image" I'm worried about on a brevet is the "Can a motorist see me in low visibility conditions (rain, fog, or dark)?"
The rest is utility. No leather bags for me, steel frames because that's what I have, geometry is stable (for a mind that wanders after hours on the road) and comfortable (for a bum that's been out there with the mind). Fenders? I start drying off 30-60 minutes sooner if I'm not getting splattered after the rain has quit, much less been soaked front AND back while it was coming down.
YMMV, of course. As long as you're enjoying the ride, it's all good.