Bit of a bump but having been considering a remap on my own 3.0TDi I stumbled here.
After a bit of googling at this Chip Express I wouldn't go there, it's a box that hooks in between the fuel pressure sensor and the ECU. So all it's going to do is fudge the signal to increase/decrease the fuel pressure as it see's fit.
A proper remap (Revo, Celtic, Darkside, Bluefin, etc) alters the fuel map, boost regulation, shift points, etc based on the ACTUAL data sent from the cars sensors, it does not remove any of the safeguards and doesn't fudge signals that the ECU relies on.