Subject: Which cold air intake design would be most efficient?

I'm hoping you can answer these questions for me.  There's much debate 
over which of these two air intakes is more efficient/provides the most 
horsepower.  One is made by A-E-M, and it is made of lightweight aluminum, 
zirconia based powder coat.  Its diameter is 2.5" throughout the inlet 
pipe.  The other is made by Iceman, and it is made out of plastic.  It 
steadily decreases from 3.5" to 2.5" in diameter as it gets closer to the 
throttle body.  Both have the same filter on one end, and they both 
connect to the throttle body (at a diameter of 2.5").

Question #1: Neglecting the materials used, which of the two intakes will 
provide more cold air into the throttle body?  Will the steady decrease in 
diameter cause more friction -- leading to warmer/less dense air?

Question #2: If the general idea of a cold air intake is to get the most 
cold air into the engine, which of these two will do a better job in doing 
this?  Which one keeps the air colder as it travels through the intake?

Thanks!

Re: Which cold air intake design would be most efficient?