I've since seen the QB items, big money tho'.
My understanding also is that the 999 air tubes deal with resonance noise reduction by having a smaller tube formed in the plastic at 90 deg to the air flow which creates a noise at a frequency that counteracts certain areas of the frequencies generated by the induction. It is possible to cap them off for more noise but I do not believe that it provides a tangible net gain in performance.
I do not know if the QB items are larger in air flow terms than the originals.
Again, given the high prices I have decided to leave mine alone for the time being, with the resonators intact.