like me, i thought diesel was the way to go, went for a 170 dsg Passat,(ok its an estate) after 4 months, im going back to my roots!, get the GTi, MUCH MUCH BETTER!.
Your dealer is lying through his teeth, the GT TDi is alot slower. Try the GTi dsg, much more fun.
If you have around 15-16k to play with by the sounds of it you do, look on
www.volkswagen.co.uk, used cars , look for GTi with dsg and for the same money you can bag a good GTi with dsg for same money. (like im doing)