For me, the advantage of cartridge pads is not the economy (there isn't any) but the ability to slide out to clean and replace without having to readjust the pad position. On road calipers, that's not a chore, but on V-brakes that are adjustable in three degrees of rotation and one degree of translation, times four, it's a pain in the butt. Eliminating that hassle, only remaining pain was that the tiny-allen pad retention screws in front are blocked by the fork, so I replaced those front and rear with 7mm external hex screws, loosened with an open end wrench.