A vehicle with larger mass would tend to take longer to come to a full stop. AWD/4WD systems I don't believe aid in braking and/or steering situations, especially if you don't have the right tires for the road to begin with. Driving a vehicle that sits high off the ground, be it an SUV, CUV, truck, or van gives one a false sense of security, even doubly more so if it's an AWD/4WD system but you're an overly confident driver or driver who's driving ability is greatly lacking.
Know the limits of your vehicle, the environment you're under, and your ability and one should be fine on the road with any time of drive train and vehicle.