I live in the PNW. I put on full coverage fenders about the middle of September and take them off about the middle of June. If I know it's going to rain on a ride when I have the fenders off, I put on clip-on SKS fenders, lengthened with old fender scraps and pop rivets. We don't mind the rain particularly. One does have to adjust riding style slightly and have good wet-weather tires, and it does get the bike dirty. But it cleans up nice. We don't melt.
We have a CoMo Speedster at 36 lbs. stripped. If one goes to one of those bike calculators, like this one:
http://bikecalculator.com/veloUS.html
one can see that one is actually not much impeded by a pound of extra weight, spread between two riders. Adding one pound to our rig increases our time up a mile of 5% grade by 2 seconds, or would require us to put out 1 additional watt to achieve the same time. This might matter if we were pro racers, but we are not.