WHAT IS THE DPF SYSTEM WHY ITS USED? 
Dpf catches those nasty nox particles from diesel engines and collects&burn those to provide cleaner exhaust gasses.
 
disadvantages of DPF system?

In time dpf gets filled of this soot that accumulates in dpf blocking the natural flow of exhaust thus choking the engine of its peak power. Via physical remove of this dpf "cell" we free the engines exhaustflow and allow turbos to spool up and keep higher pressure for long periods than with dpf. Dpf removal might not be leagal in your country, check local laws.

WHAT IS DPF CANCELLATION/OFF SOLUTION? 
We stop the regen from happening via a switch in flash, combining switch with needed dtcs for complete off solution. Just keep in mind dpf off solutions are not to be used on road, solution is intented for racing use,