Nope it weighs much less for a reason. Under load it doesnt pull as much power from the engine like it normally would giving a quicker response to load. A fast turning heavy pulley takes more force to rotate and a load compounds that effect, its also larger diameter and not working the pump as hard.
PS Pulley is installed! It is indeed a small change; the steering feel is slightly firmer, but it feels more controllable and even seems to track straighter. Power gain can probably be only seen on the dyno, but I do feel as if it is a bit more responsive in the low rpms. Recommended mod overall!