Well, with a short ram intake as it's been dubbed in all the car magazines, it's a good deal louder at lower rpms, as it's basically closer to the car, in fact, probably louder all togather, Though I will say, that the CAI, which is the long tube design you mentioned does sounds different completely. I'd say it's not really a matter of louder or softer, as anything you run with an open filter will be loud as hell, it's more just a matter of which makes more power, that being almost any of the cold air intakes.

As George said, the ice box is a nice piece, is very quiet, and hardly noticable. I had the Injen CAI before I bought the ice box, and am very glad that I switched. It's less than half the volume, and I dont know about throttle response, but it does perform as well if not better in most applications. Relistically, on the dyno, at least on my car they made comparable power, basically just making small amounts of power in different places, but as far as sound quality and maintenence ease goes, the ice box is definitely the way to go hands down. If you plan to do a turbo or supercharger setup, you may want to consider an open filter, but for all motor, I run a 2 liter with Toda Spec-C cams and a 70mm tb, and as far as I can tell, other than quieting it down, the ice box didn't have any adverse affects over a cold air style intake.

Good luck,
Aj