Touran 2.0 TDI DSG; 140 or 170?

Hello everyone, this is my first post. I hope some of you can help with my query.

I'm just about to order my first Touran: 2.0 TDI 170 DSG. I have been quoted 8 to 10 weeks delivery. (This means I will miss out on the current £1000 off offer, which runs till March 31st)

The thing is I have a chance of getting the 140 DSG version ex-stock for immediate delivery. I had my heart set on the 170, but the price of this 140 is very attractive. (especially with the -£1000 offer)

Should I wait for the 170? Or get the 140?

With the DSG gearbox, is the difference in mid-range acceleration (30mph-70mph) between the 140 and 170 really that noticable in a car like the Touran?

[I test drove a 140 DSG. But the only 170 available was a manual Passat, it felt a tiny bit quicker, but wasn't a true comparison.]

I'm a bit confused. Have any of you had experience of both 140 and 170 DSG?

I suppose I could get the 140 and if I'm not satisfied with the performance get it re-mapped up to 170. (I suppose this is what VW do to the 2.0 TDI anyway!?) But how much is this, what effect would it have on my insurance and is it really worth it?