Bill_the_Bear, don't want to turn this into a CTR bashing thread (as I love the cars) but you could gently remind your pub friend that the FN2 does without the independent rear suspension in favour of a cheaper, less-beneficial torsion beam; you could also remind him that only the Championship White edition came with a proper LSD; you could point to the fake exhausts which hide microscopic pea shooters behind them; or mention the wonderful rear spoiler that is a triumph of design over function. At least when VW do design, they still manage to keep the practicality.
As for the GTI, I think white is spot on for the MK7. So you get a thumbs up from me.
Returning to the topic though, I very much doubt a R tdi. Not even Audi offers a faster diesel in the A3 range and Audi is arguably the more appealing brand in terms of fast diesels. In fact, Audi don't even offer a competitor to the GTD (in terms of a unique performance diesel flagship), instead offering the engines in a variety of trims. But then again, they don't offer a GTI rival either and instead lump the 217bhp engine in amongst the "standard" trims.
And then we come to the argument in favour of diesels. Which invariably is cost. People might argue they like the torque, but a big V8 will offer plenty - the problem is the cost of running the V8. So the logic is that someone would pay... let's guess around £32-33k on a Golf R tdi, to save themselves around £2-3k in fuel costs over the course of 20-30k miles against a £27k GTI.
Take you 2 years to play catch up with the GTI.