Top-o-the-line Race Cassette
For those racing MTB and running 10-speed SRAM, this is your cassette. It's nearly 60 grams lighter than the XG-1080, and its skeletal design minimizes debris clogging the cassette.
The downside is obviously the price, as its not inexpensive. If it wasn't being used for race purposes, I'd probably opt for the XG-1080. Four stars for that reason.