Yeah I also think this now after doing lots of reading. I test drove the DSG6 box and it was lovely, so the only downside I can see is the additional noise when cruising on motorways vs a DSG7 box.Honestly think you should get the 2018 model. The 6 speed is a good box and you don't have to worry about the styling.
It reminds me of Eddie Jordan talking about Yachts :O He was asked about Ferrari's ridiculous expensive Yacht in Monaco. He said something along the lines of.
"If you sat on a 10 million pound yacht, and your unhappy because someone has a 500 million pound yacht to the side of you, there is something wrong with you, not the yacht."
And the the 7 speed gearbox isn't THAT much better than the 6 Plus the 6 speeder is on a none WLTP 'bodge job' car. Remember these engines were never originally designed around the new WLTP regs. So I'd say your safer with a MY2018 car.
The only thing stopping me buying the 2018 model that I referred to in the OP now is that I don't need it until January and they want me to pay the full amount now to secure it.
Sigh, decisions decisions...