The SDV6 also suffers from the old cross-over pipe issue that plagues earlier V6 diesels. That's a body off job too and a 4-figure bill (£1600 last week, so I know sadly). 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Back when I bought my RRS in 2010, I drove the 3.6 and the 3.0 back to back, and preferred the TDV6, so faced with the option of a used 3.6 or a new 3.0 I ordered the latter and I loved it. I would not fuss over any prediction of reliability, instead go for the drive train you prefer in the best condition (including its documented history) you can find.

I think the late 2009 facelift is an important one, personally. The 2012 onwards look and 8 speed is probably nice, I never drove one, and the power tailgate is more modern but the deletion of the split tailgate a shame. A spanky MY2011 3.0 is not to be sniffed at in HSE Lux or AB trim... L405 P400e Autobiography (MY2020)... Silicon Silver / Espresso
RRS TDV6 HSE Lux (MY2011)... Nara Bronze / Arabica - now gone!