Yup, would be good with a video showing the improvement
I have tried doing similar things earlier and it's not possible at all on wet tarmac, just end up spinning one wheel. It is possible to do powerslides but you have to be very abrupt with either throttle or steering (weight transfer) to ensure both wheels let go at the same time, and once sliding you have to maintain a very large angle of drift or it will snap back in line rather abruptly. Much nicer and more controllable with the Quaife
Strange that they don't have one for the 123d actually, some times they don't list every available diff on their site though, always worth giving them a call
Very service minded people!
I'm seriously looking forward to winter now though... even started looking forward to rainy days just so I can feel the diff doing it's job!