Personally, I like modern S/A drum brakes; not everyone does. But it takes the guesswork out of a retrofit where you might be anguishing over which length of reach you need on caliper brakes, or just prefer a hub brake option. Also doesn't need any braze-ons -- either canti studs or disk tabs -- to work with just about any bike. Probably wouldn't use them, however, on a bike with carbon stays/fork...