I love the Sram red cassette. The 11-26 cassette is a perfect training cassette – and I think its the perfect ratio for racing hilly courses as it offers a full range of gear ratios. Normally there is a trade off, i.e if you want a 25 you end up losing the 11... But with the 11 -26 you have the ability to take on the hills on the 26 and monster the descents on the 11.... Yippee!!
The cassette is crazy-light and the fact that it is machined from a solid piece of steel is pretty cool. It's also so easy to clean by just spraying a little GT 85 between the cogs and then allow it to drip off.
The chain/cassette combo is slightly noisier than Dura Ace, but not to the point of being distracting or disturbing. The power dome has a cavernous clunk when you change up but this doesn't effect its performance...It works seamlessly with my other Dura Ace components
Its brilliant... but it comes at a price, at around £150 -£175 its not cheap!!