Got mine in November, I have covered just over 8000miles in it and the car is great, it was good fun in standard form and a decent handler but as I like a bit less roll and better body control ( I have not had a car on stock suspension in years) so I had the AutoDelta Coilovers fitted which compliment the car great, too expensive though, if I had the time I would probably have gone for KW setup instead as they allow for more tuning of the setup and work out cheaper, I had a couple of issues with the GT, notchy gearbox with difficult selection of 6th, this was fixed by dealer and is now sweet, the 18" alloys also rubbed the rear arches in stock form when carrying 4 fat mates + me which was a bit annoying, the dealer tried refitting the rear arch liners and that helped, the uprated suspension helped more though
and my final problem was the rear reversing light cable snapped, seems common and now fixed, all in all not too bad, judging by experiences with other new cars from myself and from friends with other brands its not unusual to experience minor issues with a new model, Oh I have a squeaky drivers seat but hey you'd croak to if you had 19+ stone of me sat on you
Overall I am very happy with it, in fact as time goes on I am beginning to wonder if I will go back to a petrol car the more I get used to this JTD, I never thought I say that
If you are buying a GT get the V6 or the JTD, in my opinion the 2.0 seems a strange choice, its barely quicker than a JTD and judging by the mpg posts on here hardly more economical than the V6 when driven with a bit of spirit, the torque of the 6 or JTD just make driving easy and suprisingly enjoyable, suits the car.
Of course it would be tough for me to buy a GT right now knowing that the Brera/159 is literally around the corner, I would want to try them first, end of teh day the GT is on an old chassis, sure tweaked a bit but while good its not class leading, depends on the timeframe you are looking at .