here is another way of looking at it Kev.
My brother in law owns a 2.4JTD 10v
I own a 2.5 V6 24v Q-System
In the past 10 months so far including insurance, road tax, servicing and lastly parts, repair and labour costs he has spent £1200 more than me
So the £1200 I have gained has more than paid for my extra fuel expence.
It has nullified my brother in law's fuel economy.
Then there is the 5 days that he has had to take off work in order to get the JTD repaired.
Mine hasn't even given me the slightest bit bother.
Not saying that JTD's are unreliable, they arent if looked after... But even I noticed with my old JTD that they seem to be in for replacement items more than the V6 due to the nature of EGR's, MAP sensors, Turbo's etc. Then there is the torque of JTD's which bring further issues with clutch life, driveshafts DMF's etc.... Something the V6 never seems to suffer with as much, less complicated in many respects with a tried and tested power & transmission unit that has been round for a long, long time in other variants...
Don't just look at the fuel economy on a V6, it certainly has far better benefits to offset it.