I do not like to argue with Nick, the holes do provide more air, but in this case it effes up the vacuum tube going to the slide because there is not as much vacuum any more. the tube relies on the chamber in the box to work properly. if the attempt to get more air is the goal (and for most of us it is) then the tube needs to be in the air stream, like the open K&N kit does. and other aftermarket ones that maybe Nick sells, not sure.
The hard mount is a great improvement for sure!! But the slide ass'y needs a pressure differential to be most effective and responsive.
Rog