So visited my local Performance after a long absence. While being impatient with the slow cashier, I went perusing the parts department instead. Nothing really excited except there this cluster with the red body caught my attention, and the cogs were so smooth they LOOKED LIKE GLASS! Makes me wonder how long the look lasts, 10 miles?
I've had a long day, but what you're saying doesn't seem very clear.
You were looking at the SRAM Red Cassette? The recent issue of Bicycle magazine, or whatever, talks a bit about this. They say it's all steel, vs. the competitors titanium/steel cassettes. They suggest that it may last longer.
The shine, if properly cared for will probably look good for quite some time, only the teeth would show wear.
The titinium vs steel argument is an old one. I was only commenting about the finish. Of course it's metal, apparently polished to such a high degree that made it looks like glass. For u who are style conscious.