Most noticable difference is the throttle response. Gives a better pedal feel and the throttle is more responsive. But I think this is pretty common across the board for larger Bore TB. As for Horse Power Gain??? Hmmm it's hard to say as this was installed as a part of a series of upgrades.

But it makes sense that it will benifit the system. As funneled air/water has better velocity and is less turbulent. Take for instance a filter design Like Akimoto Funnel Ram system or the Velocity Stack that AEM incorporates into their Filter Design.