Again it depends on what you want to do. The Surly is known to be a tank. That can be good or not so good. You are in SF? Maybe a lighter bike would suit you for the hills...any less weight is good. For more distance...maybe the Surly. I wouldn't want to use cantis on SF hills.
I did messenger work in SF, so lots of fast descents and emergency stops... Cantis are more than adequate - they generate as much braking as a bike can take without flipping on a steep descent. Discs are really useful in the wet. I'd prefer discs myself, but I'd make a bigger thing of them in Seattle or the UK than SF.