quietglow

A recent proof-of-concept 80 mile ride on my fix went well (neither I nor the bike broke despite the best efforts of all the hills), so I am contemplating both an upcoming century and a 200k. Both rides are not terribly hilly. My question for the groups concerns brakes:

Is there a general consensus as to whether two are a good idea for century and longer distances? I did my recent ride with a single tied to a cyclocross lever -- my normal around-town setup. I certainly use the brake more on longer routes to preserve my legs. I'm in Chicago, so most of my training routes are pancake flat, and I'd rather not have the brake clutter if I don't need it.

I can see the theoretical pros and cons (i.e. a second brake would be nice for redundancy), but I am more looking for first hand accounts (i.e. "dude, you're gonna hate mile 110 without a second brake" or "I have ridden 600k brevets and almost never used the rear brake" etc.)