I'm getting the whole kit and caboodle.
The whole DSC question has been amply covered in another discussion... But know that DSC improves the capabilities of ANY car. It's been banned from open wheel racing, for providing an unfair advantage.
The question you need to ask, is if the car is REALLY good on it's own, do you need the little bit more if can provide.
Personally, for about the price of a replacement bumper, I'll take it, and leave it switched on to protect my investment. Hope I'll never be stupid enough to need it.