First time to ever change out a cassette, wow a very easy process. After replacing the cassette check out shifting with your chain and your back on the road again. 10 minutes max to replace a cassette. Faster than replacing a flat tire! Save few bucks, do it yourself. My old Shimano cassette a little over 8,000 miles still working but thought with a great price at Bike Tires Direct why not replace the cassette. Shimano TOP quality products along with Bike Tires Direct, my go to online bike store.
If you can't spring for the ridiculously priced DA or SRAM Red cassettes, Ultegra offers great quality, reasonable weight and a wide variety of gear-size options for a very affordable price point. I own at least six of these cassettes, in various tooth sizes, and they just do what they need to. Before living in Maui, I raced CX every year in Oregon and used these cassettes in brutal conditions where they'd get completely abused, packed with mud and debris and forced to keep on going. After post-race clean up, they were good as new. Important to always grease the splines on the cassette body when installing to extend the lifespan of both cassette and cassette body.
I am still running 10 speed. Needed a new cassette for a new Hed wheel. For $XX, these are incredible deal! The finish holds up really well, too. Seems to be more durable than Dura Ace for a lot less $ and just a little more weight.
Shimano knew that the Ultegra 6800 cassette would reside as the heart of the new 11-speed system, which is why it devoted considerable time on a feature known as 'rider-tuning.' What this means is that you receive an updated range of useable gearing options with the advent of the 11-speed design.