Brilliant for folks in flat cities riding to and from work. That's the environment in which they got popular 100y ago. For hills def need rim brakes or discs for flexibility of use. BMX racing in early 80s we used the lightest rim brakes and levers we could find. I had couple of times snapping the levers and even the brake arms before fitting with really strong machined aluminium ones which lasted me 3 years before I stopped riding.