I think I remember reading something similar to that, JT. I can't remember if it was Ford Muscle, or MM&FF. I do recall that they tested air temperature at the filter in each situation, and found there to be no difference between the fenderwell intake or the airbox with the silencer removed.
I have heard that the metal versions will retain more heat, which as we know isn't beneficial to air induction.
Just don't do the open element filter like my '88 has.. you just suck in hot air from the fan (the 3000+cfm taurus fan in my case) and from everywhere else around the engine compartment. FWIW, I believe Kenne Bell said it best, something to the effect of: "Open the hood of your vehicle, start the engine, climb in to the engine compartment, shut the hood over yourself, and take a deep breath of all that hot air. Next, stand outside in normal weather and take a deep breath. Quite a difference.."