You'll probably get reasonable behaviour with just the P (proportional) part of the PID loop - reducing the drive
as you approach the destination has a strong braking effect if the H-bridge is set up for fast decay mode. Just
switching it completely off doesn't have active braking.
Resistors in the H-bridge sound like a poor idea - current controls torque more than speed, resistors waste
battery power too, and reduce the braking effect. Using PWM isn't to be discarded lightly I think.