Hi Michael
I no longer have my Jaguar XF.
However, I can say that the Bluefin Re-Map did produce a noticeable change in the acceleration and torque of the XF.
From standstill, the lag was reduced dramatically, however, there was still a lag. albeit, only very slightly.
The great advantage of the Bluefin, is that you can remove the re-map at anytime and then put it back on at anytime.
It is a very flexible tool and I believe, you would be very happy with the results.
Hope the above helps with your decision making
Good luck
Michael