Q2 now fitted and other work done. Had the opportunity to dive it a bit and assess the changes brought about by the Q2 diff.
First thoughts were a little disappointing - lost the struggle of controlling the torque steer and feared a less satisfying drive. These initial thoughts almost immediately replaced by the realisation of just how much better the car is. Torque steer is, to all intents and purposes, eliminated and the front end feels more planted and responsive. Traction control will still kick in, but later and before I can get into difficulty.
An expensive upgrade, yes, but a worthwhile one. I now understand why no one tried to dissuade me.
Thank you to all of you who offered advice and encouragement.
Living life in the doghouse!