Did a bit of digging to answer my own question on the torque vectoring. Looks like a pretty good system with torque vectoring by power and brake.
Under the heading Electronic stability control (ESC) page 227 of the model year 2019 owners manual
"ESC operates in combination with the Traction Control (TC) system. It prevents the drive wheels from spinning.
Torque distribution is a special feature that allocates the torque to the drive wheels before the ESC intervenes. When cornering the wheels on the inner curve are braked individually. Additionally engine torque will be delivered to the drive wheel on the outer curve. This reduces the tendency of understeer and improves traction when cornering fast"
It then goes on and on about various modes including a special competitive mode exclusive to VXR !
Normal sport mode, (available in Calais V) when activated "all wheel drive supports active dynamic driving of the vehicle"
Looks like engine sound enhancement intensifies interior engine sound...fake engine noise through the speakers...debateable whether that's a good thing.
Sport mode also adjusts shock absorbers, steering feel, and automatic transmission shift points optimised for dynamic driving.
Looks like its well worth hitting the sport button or VXR button for those with a VXR.