I have the comptech ice box, and dut has one on his ek9.
I find myself repeating this a lot-
The design of the ice box is to keep the high rpm hp curve, throttle response, and easy filter access of a short ram intake, while mating it to a cold air intake source that has little to no restriction. Normal short rams get some of the benefits cancelled out from being in the hot engine bay air, so its best to mate it to a cold air source.
The cold air pipe going into the air box is much larger than a normal intake pipe, this is so the short ram part of the system stays isolated and retains the throttle response and air flow.
There is an air horn at the beginning of the induction pipe as well as inside the filter, horn shaped pipe openings reduce air turbulence as opposed to a normal clean cut, in turn you get more air velocity to fill the combustion chamber.
Personally, I bought the plastic ice box along with the filter and skipped on buying the metal pipe that goes with it, I just got a much cheaper ITR rubber intake pipe which also reduces heat soak. King motorsports makes a replacement silicone ITR pipe that doesnt have the flex bends in it that cause turbulence.
At the end of the comptech system there is the air horn that is swivle-able, so you can point it towards the front bumper (and route it to a direct air hole), or upwards like the more expensive mugen intake, which doesnt swivel. Inside the pipe of where the swiveling part joins together there is a small lip that sticks out, this should be dremel'ed and sanded smooth.
The only problem with this is comptech went out of business in april and the any thing from the company is going to be harder to find. I've already had to stock up on the cleaning & re-oiling kits for the filter.
The competch intake will win out over the just a spoon drop in filter, it has more filter area, and it has a large cold air tube along with horn shaped inductions on the openings. You could make a CAI, Short ram hyrbid using the spoon filter but I don't think it would end up being as good.