I'm a Fred. I left my reflectors on. 90+% of my rides are during the day, but....occassionally I'm out very eary in the morning or in rain and fog. Not dark, but not full daylight. On those occassions, having the reflectors gives me just a boost of visibility.

However, since seeing the reflective sidewall tires (thanks TE for expanding my knowledge!), my next tires will be the reflective variety and I'll probably un-Fred myself of the wheel reflectors. But, not the rack, the rack reflector, the handlebar bag, the dork disk.....sigh....