On the Corrado for sure I can spin away and understeer through a corner if I so choose, but if you get the power just right (which you can with a N/A engine and is rather more difficult on a turbo engine), it will actually flatten the car down on its haunches and pull it round the corner quite nicely. So, personally, I don't see a significant need for an LSD on the road. On the track or on gravel/mud is a different matter obs.
Caveat obviously I've not driven one, but I'd be surprised if the VAQ can't respond pretty much as fast as the ABS and traction control can, i.e. on barely a fraction of a turn of a slipping wheel.
It won't be out-drawn by ABS, but the actual differential won't beat an ATB, which doesn't have to respond to an analyzed scenario or, to break from proper definition, it doesn't have to "react".
An ATB is always engaged; always functional. There is no delay in operation, and it always does the same thing, every time.
With a good mechanical traction aid, you can flick that ass out just short of steering lock, plant the throttle, and it'll pull you right back in line; every time, in precisely the same manner. No electronic system can match that.
ABS grabbing a wheel to shunt torque is just icing on the cake, and isn't even always desirable.