I prefer power brakes, if your car has power brakes I myself would leave them. I've had manual brake cars in the past and it takes more effort to stop and power brakes are safer and they don't cost any power.
I’m not sure power brakes are “safer” as you say. A correctly done manual brake set up will stop anything. With power brakes you are limited to how much cam timing you can run. As intake manifold vacuum drops, power brakes become less effective to the point the car won’t stop without 2 feet on the brake pedal. Manual brakes take up less space in the engine bay, weigh less and done correctly will stop like power brakes, and you can run any cam you want.
