I got this done 6 months ago. It didn't need done I got it done to see if it would improve my mpg.
I seen on the guys facebook page that after the process was finished the car would cough and sputter black smoke. Results:
Cost £140
Better MPG-No, same
Cough black smoke? No...not even a bit
Outcome? Well, not writing it off..Maybe if DPF has failed and blocked then it might be more benificial but for me I wouldn't know the guy had done it if it weren't for me watching him.