Canti's are a little harder to setup since you also have to adjust how far the the pad sits from the brake arms. Moving the pads farther from the arms can dramatically increase your stopping power. There's certainly nothing wrong with V brakes though, so it's really a matter of preference. I have cheap shimano altus canti's on an old mtb and they went from total suck to locking either wheel at will just by pushing the pads out.