I have a Spesh Singlecross for a commuter now, and I have cantis/Kool-Stop salmon pads on there. It works plenty fine to stop me even in the rain at the bottom of a 40mph screamer descent.
Where I would consider a non-disc system to be inferiour is in a PNW winter with all the grit on the wet roads; I tear through brake pads, and a pair of rims only lasts me about 7000 - 8000 miles before I wear out the brake track... but I stick with it just because I already have the equipment and don't want to spend the money on a disc brake generator hub and a new rear hub.