so with one fitted are we talking on par with GTI performance?
Forget being on a par with a GTI below 30mph (you can't get all that power down quick enough), above 30mph, I would say that it exceeds a standard MK7 GTI - like Hyperspace on the Millenium Falcon (OK, slight exaggeration).
I find the bite/release of the autohold really hinders a quick move-off from standstill - it always feel like if I do it too quickly, i'll stall the car.
In Gear, with 26PS less than the MK6 GTI, the unaltered, stock MK7 GTD exceeds it in 4th/5th/6th from 40-80mph.
With dual channel box fitment and 15PS more than the standard MK7 GTI, how do you think it will fare against one? I'd take an educated guess that over the 40-80mph range, a GTD with only 210PS would keep up with a 220PS MK7 GTI due to the extra torque.
My overall mpg didn't drop with the box I trialled. The extra power will probably only come into play for 5% of your drive (unless you drive like a nutter), but it's nice to have it in reserve.
Keep thinking about getting another box, if it ever stopped raining then my Bridgestones would not be an issue.