No brother, I don't think so. GD has regular drum brakes. And I do not find anything exceptional in them - they are working fine. In fact I am not a hard braker, so I feel troubled while trying to stop my GD - it takes time to slow down, no instant jamming. So I took it to Suzuki mechanic who took me to a ride on my GD. While he was riding it at 60 km/h and I was talking to him, he suddenly applied brakes and bike instantly came to a stand-still! I was amazed how he did it without the tyres screaching or bike getting unbalanced.
I have not been able to reproduce that braking performance (guess I need some classes from him), but I cannot say that GD's brakes are not good