Center diff vs transfer case

[Diamondpilot]

I rented a GM SUV last winter. Forgot what it was but it had AWD system with a traction control that used ABS to prevent slippage of single wheel. I assume that it simply applied break to the wheel that had tendency to slip.
When disengaged I could do doughnuts on a snowy parking lot at will. When engaged it was near impossible to do so. Also climbing very steep hill on snow when disengaged I would get stuck not too far from the bottom. When engaged the car climbed up only with some hardly detectable slippage. In other words I was impressed how well it worked. The great thing about system using electronics is speed of response I suppose. I also read somewhere that it allows for an "active steering". When steering wheel is turned the system applies certain amount of breaking to the wheels inside of the turn.

My Nissan Titan has a system on it just like that. They call it VDC or vehicle dynamic control. You can turn it on and off at will via a switch or its automatically disengaged when you put it in 4 Low but is still on when in 4 High unless you manually turn it off. It also disengages when you turn on the Detroit lockers via there own switches. Its hands down the best 4x4 vehicle I have driven.

Chris