Just thought I'd post my 6 months of GTD ownership as well. FYI, mine is a 5DR DSG
So I have done around 12k miles in mine. The car has had warranty work, been crashed into, but I've also had some lovely moments in it. The following list is in no particular order; just what springs to mind first. It's mostly negative as that what I sticks out the most in my mind.
1) Slightly disappointed on the fuel consumption. Average is 42. I can get 50 if I drive like a nun, or 35 when going for which isn't too bad I guess. I was just hoping for more.
2) Overall, LOVE the Adaptive cruise control. On the DSG, never having to change gear or anything is brilliant in traffic jams. I do however struggle with it on busy motorways as the distance it leaves is huge. It's fine if just sitting in the fast lane, but if changing lanes, you need to leave 3 or 4 chevrons apart.
3) Front windscreen wiper is rubbish. I need to get this changed
4) The front right day time running light was changed as stopped working
5) The cars suspension rattled for 10k miles before I could be bothered to get it sorted. Something to do with a common fault. Something to do with something mechanical (over my head). All sorted now.
6) I find the DSG a bit, all or nothing. I don't have the adaptive chassis, but the car mode is set to sports, and I find I'm either super accelerating, or not really going at all.
7) The power is good. I do love overtaking a handful of cars with my winky on bombing past them.

No other GTD/GTI/R driver flashes me back

9) The Pro Nav has frozen more times than I can count. Doesn't also work in the cold.
10) The white gets dirty very easily. It's had to be cleaned weekly.
11) The heated seats are amazing. They are on 90% of the time.
12) Grown to really likes keyless entry. Although I do hate it as I'm paranoid I never lock my car, and can't physically check either.
13) It get's looks from all sorts of people. In a good way.
14) The suspension can feel a little hard over proper bumpy roads.
15) I see far to many white GTD's on the road now. 3 are on the same street as me.
16) I LOVE the rear indicators. Far better than any Audi S Line ones.
17) The xenon dipped beam is poor. Only about 2 meters in front of me.
17) THe white fog lights rather than yellow lights do the business. Look like little fangs.
18) Nice practical car. Has taken 4 down to the South of France. All luggage (although a squeeze) and a cool box.
19) Never managed to get the Sat Nav to update maps. Probably down to my error of not reading how to work the SD properly.
20) Had something to do with the window replaced under warranty.
21) Washer water lights comes on a lot. Although I do use a lot, after about 3 squirts on a complete refill seems to set it off.
22) The GTD alloys look the sh!t.
23) It's quite a wide car.
24) The GTD/GTI/R steering wheel is 10x nicer than the other Golf ones with small controls on the wheel.
25) The car jumps around a lot when braking and acceleration over cats eyes.
26) Mixed views on the sound acculator. It can sound like I'm revving the tits off it.
27) Good size pockets for drink and 1 litre bottles.
28) It has a spare wheel!
29) It can cover series ground at 120+ without any fuss.
30) I get through quickly (above would suggest why though)
31) It looks good on the drive
32) I find the seats really comfy
33) The glove box is small.
34) I only found out last week it has a storage space under the driver and passenger side seat.
35) It is very easy and comfortable to drive.
36) Did I mentioned I see a good 10 of these daily now?
37) It's super cheap to insure
38) Autohold is really good. Foot off the brake, holds it fine. Accelerate and off, although can be slow to react.
39) I've had auto stop/start turned off the whole time as I just don't like it in an auto as is slow to start. On a manual it's fine.
40) Used the paddles once, and then couldn't be bothered again.
41) I put it is "S" for overtaking. Never tried without to be fair. Does the trick, sounds good too with the sound acculator.
42) Is fairly cheap to get body work done as a full panel doesn't need painting because it can be blended into the bold lines.
43) I think it's a very sexy looking car.
That's it for now. All that springs to mind. Hope you enjoyed reading some of them.