I do a lot of mixed riding on a club-style road bike/light tourer with long drop calipers. It has clearance for 32mm tyres + fenders so can cope with pretty rough surfaces but I find that the calipers are much better than cantilevers on my tourer, they have all the stopping power, lighter action and better modulation.
Make sure the bike has threaded eyelets for rear rack and front fenders , this will be really useful some day.