Just my 2c - I have a Trek Valencia and a Specialized TriCross Comp. In my experience, the stopping power on the Valencia's disc brakes is noticeably better than the stopping power on the TriCross's canti brakes. I'd retrofit the TriCross with disc brakes if it was economically feasible. Honestly, when I switched to a more road-style bike for commuting, a lack of any options with disc brakes was one of the downsides.