Spent considerable amount of time playing Witcher 2 (more than 200 hours totally + 10 hours past week on patch 1.3), I gotta say I never found it to be very very very obvious while playing or never understood as to escalate the above behavoir; Acknowledging it as
the* major crippling effect in the gameplay for all the players who mentioned about controls being slow, laggy, unresponsive or a fail.
I Must be missing something!.
Totally Agree its a set/batch of minor glitches which appears (from the video) to be cascading to the combat pool during gameplay, but..still.
Note: I do not have a good smooth video capture(free version) with correct timestamp logging to check the issue along with the keylogger, else i would have done it to confirm the *gameplayness* crippling controls.