It definitely sounds like an upgrade. The original stock aluminum sprocket was anodized but still looked like raw aluminum. The newer steel sprockets are black anodized. The copper colored 'anti-seize' sounds like Loctite was used and that is not what the factory used on the rear wheel. They just torqued it hard. You may have just paid for a SuperMax sprocket that you might not need. The steel sprocket makes no noise what ever and will outlast the SuperMax. I know. I was the first to use one and I broke it after only 19,000 miles. The steel one should last as long as the car. The belt should go for about 100,000 miles before replacing.
Hope this helps!
