I took it off to experiment with it, engine bay looks better to me and it makes slightly more intake noise.the air is being pulled closer to the engine so it might be slightly warmer but with a mod this simple I doubt it gives any kind of real gain mpg/hp, just easy and make the bay look better to me.
I used a 6 inch extension (a 2"" or deep socket will be fine) and a 10mm socket to remove the one bolt on the valve cover that holds it on.