You've got VCDS p3asa haven't you mate? Just wondering if you've tried turning the soundaktor to 0%, as I have wondered how much it is is actually used when you have S&S fitted?
Agreed on the above Peter - worth trying a car without if you can.
15 weeks for a factory car seems quite quick too?
Although they are giving you £400 extra for a trade in today, you will be starting depreciation on the GTD sooner, so it might be a closer run thing financially?
If you ordered from DTD it would save you well over £1000 on the dealer's price for factory. 8% isn't a bad deal for walking into a local dealer (mine wouldn't even do 5%!) but it's still not 12.2%!
As you said it's a fantastic car (still puts a smile on my face 1 year in), but it's definitely worth getting the spec you want unless other factors make the compromise worth it. My wife just bought a Polo and we ended up getting one at a weeks notice, which meant she didn't get the options she wanted (like winter pack), but her current car is becoming so unreliable it was no brainer. Plus she still got an 18% discount, polo discounts eh!