Do yourself a favor and try out some decent hydraulic brakes. Now only are they pretty amazing, but amazingly consistent. Even in rain, heat, cold, etc. Also it's MUCH rarer to have to undo a brake, just because your wheel went out of true.
Try to track your use, going downhill and hit a puddle, do you drag your brakes? Why? Wait till they grip again? I had no idea I had such habits.
I've tried hydraulics on friends bikes, definitely nicer, but again not enough to motivate me to switch.
That's how it is with all of these improvements. Someone will always have newer, slicker gear than me, but I keep riding. ;-)
Roads are far from clean, and if anything the debris is more abrasive than you'll find off road. I'd rather have normal dirt than tire and disc dust you'll find on the road.
Myself, I'm not getting rid of my rim brake bikes any time soon, but it's interesting to observe how different people experience cycling.