Hi there,
I have used superchips with my 2.0 TDI 140, this was a standard remap done at superchips HQ in Buckingham (not bluefin as it wasn't available when I did mine). Cost me £450, but it could cost more now.
My power and torque outputs after the remap were 186bhp and 300ft/lb. It makes an amazing difference to the performance and driveability of the car. (you can give Golf GTI's a run for their money!!)
I don't regret it for a second. Mine can only be reverted back to standard tune by superchips (but I wouldn't want to). I have had my car serviced by Audi and they haven't detected anything. My car has run perfectly with the remap for over 18 months. Just go for it.