Well, I went to APS today and had the KW V2 Coilovers fitted.
Now I am a happy A5 owner again.
Whilst I don't think the ride is as smooth etc as the stock system, it's very close and a vast improvement on the H&Rs.
The ride home was via a cross country route rather than the clogged up and boring M1 and both my son and I enjoyed the journey.
I took the family out this evening and Mrs REB says it is money well spent - so I must have done something right for a change.
So, thank you to those that offered advice and again particularly to Manor50 for the ride in his S5.
Thanks also go to Ed and his team at APS for a job well done.
Just the remap to go now to complete the picture.