My preference is for interrupted cable housing. Makes servicing cables easier, provides better brake feel, and it looks better. Two of my vintage bikes have full length brake cable housing held in place by cable clamps. That is the way things were done back then. Since the brake housing is spiral wound it has more sponge feel to the rear brake than other bikes with interrupted housing.
FWIW, full length housing for brakes and derailleurs still get dirt or corrosion in them and need servicing, especially on mountain bikes.