I'm a big fan of the GTD, and was a big fan of the mk6 GTD and yet I owned neither!
I've spent a reasonable amount of time in GTD's as a friend of mine hires them from time to time and he will always bring it round for me to have a drive in. I've tried both manual and DSG and don't have any particular preference, the manual is more involving and I love the way you can use the torque to slingshot out of corners and the DSG suits the narrow power band but hides the torque kick. The DSG launch control actually makes it seem a lot quicker than the figures suggest but I guess that's because you're just a passenger really.
If I had a company car allowance the GTD would be top of my list. However, here's the thing - I'd quite happily buy one as a private purchaser too as the power delivery suits modern traffic conditions and with the extra fuel range it's less time stood shivering on a garage forecourt and at current prices must be significantly cheaper to run than a GTI.
When I saw the first pics of the ClubSport and immediately hated the front bumper on it then it was the GTD that seemed it would be the more likely successor to my GTI when it hit three years old. Obviously a tuning box and pedal box would have been immediately added and if the Bridgestone tramping got to me then a new set of tyres would quickly be fitted...
Due to an unexpected and unplanned purchase of an R you'd have thought that the lure of a GTD would have long since vanished from my radar but...
... well lets just say if my R wasn't technically an outright purchase and I was in a PCP situation then the Inchcape email I just received showing £2500 contribution plus other discounts from dealers would sway me towards a GTD (with tuning box) over the R with no hesitation!
Am I mad? Well yes, certifiably.
But I will add that yesterday coming off a roundabout in the R there was a Royal Mail Fiat Doblo in front of me. Lets just say that the traffic was quite heavy so I didn't want to drive like an arse but by the time we got to the next roundabout the Doblo was quite a distance in front of me!!!

The driver gave me the thumbs up and a big smile.
Diesel torque isn't to be sniffed at if you're not drag racing.