About the engines

Gentlemen,

I'm about buying an XF from the era between 2008 - 2015.

Before I start hunting down the cat, I have to decide wich engine  I should choose, I'd kindly ask for your help in making this rather tricky decison.  Amongst the petrol versions there're plenty to choose from, as far as I know, from the 2.0 turbo to the supercharged 5.0. Downsizing isn't the right way, so we can forget the 2.0 turbo, the other end, 5.0 compressor, is also pure insanity for daily usage. I don't want any AWD system in my car, so the magnificent supercharged 3.0 V6 sadly has to be forgotten as well. I stand in front of two possible units, 3.0 V6 and 4.2 V8. How're they in everyday use? What's life like with the smoothly purring V6, and the angry growling V8? Is the V8 so much more of an engine, that worth the extra maintenance costs? Will the more powerful unit simply eat up the drivetrain? Currently I'm tending towards the 4.2 V8, but if You, based on Your experiences advise me otherwise I can change my mind. 

Thank You in advance: Peter