VW sudden power loss issues

[alexaescht]

Wow! How often does it clean the DPF? Does it affect the engine performance at all?

Depends on how you drive it, but I'd say roughly every 1,500 to 2,000 kms.

Engine performance – you can definitely notice. Turbo boost is increased to counteract the leaner mixture used during the cleaning process which results in a hell of a lot of turbo lag. Engine noise increases dramatically and overall the car runs like crap.
Sometimes the ECU starts the cleaning process when the engine is cold which results in stalling, erratic idling and unburnt diesel coming out the exhaust because the engine's not up to operating temp and there's not enough fuel being fed into it, which can be interesting because coming up to intersections it either will stall or you have to rev the engine in neutral while braking. Once the engine is up to temperature it tends not to stall.