Picked up the GTI yesterday, and it's good to have it back. Wimbledon VW confirmed that West London Volkswagen hadn't replaced anything or completed the proper testing plan that would have seen all the issues identified. Not only had the Oil switch failed, but another item had failed which would have also been picked up if done properly. All done under warranty, thoroughly tested and back to being as it should.
As for the Polo, I did 500 miles in it, and not once did I get the judders gearbox described above. I put that down to me being used to DSG. If you drive a DSG like you think, then you'll struggle (I know I did when I first drove one a few years ago), but if you drive a DSG as a DSG needs to be driven then it's a great box. Gaming the DSG is very rewarding, especially in such a small engine. It was a little gutless, but nippy enough to get around town. Gripes for me were the manual handbrake, it felt like going back in time and with the DSG box throws the sequence you expect right out of kilter.
Size wise, again I disagree with the comments above. It's smaller, much smaller on all levels, to the golf. The door cards are much thinner and the days is shallower, making it feel bigger inside, but it's a bit of an illusion when you actually come to put stuff in it.
A [very] small thing that made me glad I went for the 7.5 rather than wait for the 8... with the new generations of infotainment up on the dash high, the 2x vents are moved down, and no matter what position I put the vents in, when driving along the cold air simply made my hand/arm cold as it blows directly across/up/down where your hand is for the gearstick and handbrake, especially as there was no arm rest.
VW penny-pinching at it's worst however was when I was driving along and tried to use my washer jets, only for nothing to come out... I got home, checked and saw the reservoir was empty, but I didn't;'t get a warning. I checked the manual, and low & behold there's no low washer warning.

All in all, great to have the Golf back.