XF SV8 vs XFR

[Jensky]

I’m considering getting into an XF. I like the idea of the SV8 as it’ll have plenty of power on a tried and tested engine but all the other items on the car being mainly standard XF fare so the running costs should in theory not be too crazy, but lots of people seem to point me in the direction of an XFR instead as it’ll be a better drive. What’s the pros and cons of each?