Yes I have close to 40,000 miles on a stock tooth rear Tri-Metal. Best sprocket I have ever purchased. Expensive when you consider the cost of other sprockets on the market however from my experience it is worth every dollar I paid for it and then some.
I live 10 minutes from St. Charles IL, where the sell them so I decided to go check them out. If you let the folks at sidewinder tell you, it's the best sprocket on the market.
I agree it's pricey. I paid 130.00 for my rear. You get a life time warranty (if you read the details it's more like a limited life time warranty). I do like the bling and it really does appears to be well built.
I was looking to go up a few on my rear sprocket and found this site. My local speed shop also recommended them too. Overall I very happy so far.
They have hardened steel teeth (the black part), aluminum carrier (gold part), and Titanium rivots. This is to make a superstrong yet lightweight sprocket. I believe they are made in Europe for Sidewinder. They can also make custom sprockets and I will wind up getting one for my busa once my Afam is worn out.