Well Digger, there has been tons and tons written on "cold" air intakes or what I call after market intakes (I will explain that below). Having seen many cars at the dyno with aftermarket intakes see little to absolutely no power improvement I can tell you for the looks and change in engine sound they are a fine investment but for power..........go with a tune.
Now, as for the cold air part...........that is a misnomer like "ram air" intakes. Neither function actually happens with these intakes. A cold air intake does not make the air colder as it gets air in and around the engine compartment and ram air is not "rammed" into an intake and the air is not sub atmospheric. There are marketing ploys to make you think your getting something special. Air flow is usually better on aftermarket but that is only because the after market filter filters at a higher micron rate. So, is that good for the engine. Frankly, I would not advise the use of any aftermarket filter in dusty areas but highway driving is probably fine.