I'm getting my GTD test drive tomorrow, in my ordered colour of Tornado Red. It is a pity it's a DSG - i'm not a fan, i'll have to use the paddles to replicate the manual experience as much as possible rather than have the DSG hang every gear to the red line (really not necessary on a TDI). The dealer has told me I can have it for a few hours which would be nice, but i'll have to be there early to take advantage before the Sunderland Airshow spectator traffic completely chokes the local roads. I will be giving it a blast down the A19 to Hartlepool and back.
The GTD vs GTD debate never ceases (so I will add to it). I will be happy enough that on paper the GTD matches the MK6 GTI for in-gear acceleration and is just 0.3s down on the 0-62 time that I would never fully exploit. Any miniscule handling differences between MK7 GTI and GTD will not be apparent in lawful highway driving (you might see the difference trying to take a roundabout at 80mph), and apart from drag racing there'll be a car's length or 2 between the 2 cars on a 40-75mph acceleration (i'll not be losing sleep over that). For that performance difference i'll not be feeling the pinch when I put my foot down - maintaining 40mpg in a GTD will be a lot more fun than trying to do the same in a GTI.
Getting hung up over weight/handling is pointless - a 3 door GTD manual will weigh about 67kg less than a 5 door GTI DSG PP with sunroof, will that run the GTIs handling? Maybe on a track, but on the UK roads you will never notice. Driving without a passenger to balance out the passenger weight would be more noticeable (driving it to it's limits). GTI was never an option for me until I know what my commute is going to be when I have to start job hunting in 14 months time. I'd be kicking myself if I bought a GTI and ended up tripling my commute in my new job. Everyone has their reasons for what they pick and for most here, their cars will never routinely do more than 90mph on a straight road (which will bother neither car).