What your going to use the car for also may have some impact. If it was a daily - defo a V6 or even (
Shhhh) a 2 ltr. But from your previous cars you mentioned, the 2 ltr might be to far down the sensible route.
If its an occasional toy (as mine is), then the V8 does make you smile. I find the V8s is a bit more lively at the back end than the XKR, but im putting that down to sh*t PZeros. Mines isnt AWD.
Are you going to track the car, drive it in crap weather..
as other have said, try before you buy - if possible. But in the end the V6s or V8s is a nice toy to have. Only you can chose which suits you best.
IRR V8S. (Maybe going soon).
Macan turbo ..wifes.
Sunny Scotland based.