Things can go wrong with most anything, but here's what I know already about Sensotronic Brake Control (SBC):
In the event of an electrical failure, there is a hydraulic over-ride in the hydraulic unit (called a seperation valve) that will allow normal hydraulic pressure to be applied, although without power brakes.
The system is designed to "feel" like a normal brake pedal, but in normal operation, an electronic sensor is really determining what is occurring at the wheels. An obvious benefit is that each wheel is capable of being provided the correct amount of pressure.
A couple safety relevant advantages are called pre-charging and dry braking.
Precharging means that if the system detects your foot coming off the throttle rapidly, the brake system will bring the brake pads out just to the rotor, to be able to apply more rapidly when the brake pedal is depressed (not until you step on the brakes will they actually apply).
Dry braking is a feature where the brakes are applied very briefly and lightly about every 5 to 10 minutes if the wipers are operating. This action keeps a film of water from developing on the rotor surface to help reduce stopping distances in wet weather.
There is also a feature called "Softstop" which reduces the "jerk" you feel at the end of a stop. It doesn't work during panic stops.
It's going to be tricky to remember the safety precautions when servicing the brakes, as the brakes automatically apply if the driver or passenger door is opened, among other reasons, so the system has to be deactivated using the SDS computer before doing any brake work. Can get really messy if you forget that!