Well in my opinion, any gizmo that does not have a substantial pump to actually force the induction of air into the combustion chamber is pretty useless, in terms of percentage of increase n performance.
And m sure most here would agree that the vaccuum form the vac pipe will not be able to produce any substantial gain, thus the installation of this gadget even if it works, for a marginal increase is performance is not justified, at least for most of the users here, however fancy it may look.
Thus this, in my opinion falls into the same category as the sock they sold for the knob on the gear-stick, so that it would be cold to the touch and gave a better grip.
So I guess all are in accord, to trash this item?.................