Scottmac: The original poster is paying his own insurance, he's expecting it to cost him £500 a year more to insure, your circumstances (company car) don't apply to him.
As for the 140/170 example, the person in question that I know has full NCD, pays £180 a year for extra insurance on a remapped 140 vs £30 more than untouched £140 for buying a 170 = £150 a year difference in insurance. He keeps the car 3 years generally and his remap cost him £350, so he pays out £800 over 3 years for the privilege of being remapped. The remap has very little value when left on the car. The difference in list price between the 140 and the 170 is £760, and you'll see 1/2 of that back come trade in time. So £760 now, getting £380 back (170) vs £800 now, possibly getting £200 back for your remap if you're very lucky (140 remap). No warranty worries either. Still seems like the 170 beats a remapped 140 over a typical 3 years ownership. Either way it was just an example to show how remap isn't always cost effective.
The 2.0TSI costs £3075 over the 1.4TSI and comes with about £1550 of equipement that you would need to spec on the 1.4. The original poster may find that if he bought a 2.0TSI, he might've only paid £100 or £150 more than an untouched 1.4TSI to insure per year, so would save £350-£400 per year on insurance, and would have no warranty worries. If someone buys a 1.4TSI and specs up all the GT equipment and pays £400 a year more for insurance on a remapped model, they will find themselves paying out the same amount for a 3 year ownership:-
3 x £400 insurance difference + £350 cost of remap +£1550 cost of GT equipment = £3100 vs £3075 cost extra of an untouched 2.0TSI.
I am of course assuming that someone would want to spec all the GT equipment (for it to be a completely fair comparision) and that they didn't buy the 1.4TSI for it's 5mpg economy advantage seeing as they want to remap it. Possible slightly higher residuals on the 1.4TSI basic car (due to economy considerations) would no doubt be outweighed by significantly lower retained value of the non standard equipment specced.
I'm just saying that for the Roc, buying an equivalently specced 1.4TSI and remapping it vs getting a 2.0TSI and running it for 3 years is sometimes a false economy, same story for buying and remapping a 140 vs 170TDI.
Purely in a financial sense of course, we all know the 1.4TSI is sportier than the 2.0TSI.
Hope everyone is ready for another week of roc driving festivities! 
