N52 throttle response: how sharp on low rpm?

75k miles 330i 6MT. In lower rpm range, when press down throttle, it feels like the surge of power comes somewhat half a second later. I am wondering how sharp the throttle response should be?



I ve tried the press-on-throttle-for-30-seconds trick and feel little difference.



My gas mileage also seems to be on the high side, thinking of a spark plug change?