I run a 57 plate A6 2.0 tdi for my long trips to Germany.
I fitted the Tunit box to this, give iro of 170hp plenty of torque, fuel consumption is improved by a few mpg.
I sell both Apr remaps and Tunit products, I opted for the box over the remap as you can remove the Tunit box easily and move it to another similar engined car. The remap is in the ecu and is sold with the car.
Many customers chose the Tunit for this reason.