I've now had my GTD for a month so thought I'd share my initial ownership experiences with you guys. I've not covered many miles yet - about 750, but I think that's enough to form an initial impression.
Build quality; apart from some uneven panel gaps between the bonnet and wings, It seems to be OK and on a par with my previous Golf (mk 5 GT 170 diesel). I'm really annoyed that I didn't spot the uneven gaps when I picked up the car.

Sadly, judging by what I've read on various forums this seems to be quite common with VW's, but I feel it should have been rectified before leaving the factory or during the PDI. I had similar panel alignment issues with my mk 5 too. I've phoned the dealer and it's going back to be sorted. No creaks and rattles yet (keeping my fingers crossed). The interior also seems a nicer place to be than the mk5.
MPG; best I've seen so far has been 63 mpg (according to the MFD display). Overall, for total distance travelled, the MFD is showing 51.7, which I'm expecting to see improve, once the engine starts to loosen up.
Ride quality; can't say I'm noticing it's any worse on 18" wheels, compared to the mk 5 which was on 17's.
Noise levels; an improvement over the mk 5. The 2.0 CR unit is certainly more refined than the old PD unit and the power delivery is much smoother and more linear.
Favourite bits; Most favourite are the lights - both the rear LED's and the xenons! Love them.

This is the first car I've had with xenons and I'm finding I look forward to night driving and look for excuses to drive it after dark! Also like the Dynaudio. I have to agree with Asker; for the money, I think this a really worthwhile option. The front seats are good too and I like the retro styling of the cloth version I've got.
Least favourite bits; Nothing major but I've got one or two minor niggles. The uneven panel gaps. Don't know if it's just me but the rear visibility doesn't seem quite as good as the mk 5 either. Strange, considering it's basically the same car as the mk 5. Glad I've got the parking sensors! Disappointed that my car came with Bridgestone tyres - I'm not a great fan of these. Also, the absence of some of the nice little touches that were in the mk 5 in VW's pursuit to cut costs is disappointing; no chrome luggage hooks in the boot, no remote fuel flap, glove box handle isn't chrome anymore, grey paint in the engine bay.
But overall, I'm happy - Hoping this continues!