Thank you David and Arianne for your update and exlanation. At the end of the day as long as you are happy that is the main thing.
I do feel you have let the dealer off very lightly. It is obvious to everyone that your vehicle would never have passed the handbrake test on the MOT. The fact that you knew it was really bad and thus requested work on it then post MOT you couldn't even get the vehicle to hold on your virtually flat drive after only driving a few short miles home. I guarantee that had the vehicle gone to VOSA for a re-inspection the dealer would have been in a little bit of trouble.
Anyway! As your willing to put it behind you then I wish you all the best and hope you have great joy in your new XC60 when you get it. In the mean time just enjoy the XC90 the way it is supposed to be.
Take care,