The lights on my April 2016 GTI are significantly better than those on my March 2014 GTD were. Never looked into the reason why, but I would say that they are a little whiter with much better fill in and slightly better range. The GTD lights were my first experience of HIDs, and I was not overly impressed, but my GTI lights are superb and still impress me when I first turn them on.
Anyone know if there was a change to the system?