Dark headlining is standard on the GTD too. My GTD is completely standard, I don't need/want any of the options enough to add £3-4k to my car that I won't see more than 15% of back at trade-in time, other people will go the whole hog, but it will probably add nigh-on £100 a month to your monthly payments.
Here's the cynical guide to them from someone who never bought any:
DCC - Some people say they won't be without it, but the GTD/GTI standard set-up is extremely forgiving for having 18" wheels and lowered suspension.
SatNav - VW want way too much for the integration. The standard satnav is just a module that plugs into the existing screen set-up, and the pro is a ridiculous £1700.
Leather - Very pricey, only around half of it is actually leather, feels hot in the summer, it sags, it takes away some of the interior identity of the GTI/GTD.
Rear View camera - it is frequetly bought because it is cheap, but the standard sensors pick up absolutely everything, I really don't see the point.
Dynaudio. Yes it's better than standard, but in a car with lots of external noises filtering through, your typical audiophile will already concede that car audio is compromised.
Keyless: £350 for something that is standard on many lesser cars (my wife's mate's Renault Captur has it), i'm sure it'll become part of the spec in future.
Quick clear windscreen - great, if you could buy it on it's own for £250/300, but you can't you need to get a telephone prep with it as it interferes with the signals (stop using your phone in the car I say, even a hands free conversation is a distraction at the wheel).