There's not much to say about this product other than that it is typical Shimano quality. It's smooth, quiet, and shifts efficiently without hesitation. The narrow gear range of this particular cassette was what I wanted for gravel racing.
I currently use the Ultegra CS5800 11 speed group set. Actually, this group set comes with the 105 11 speed cassette. My goal was to be able to switch out seamlessly with my current wheels so when I had a chance to buy a similar brand wheel sets but deeper, I bought the CS-R8000 cassette. The installation was simple but you will need a proper torque wrench to fit the Shimano cassette to the proper spec. You may need to adjust the brake pads to make sure there is no rubbing. I did not have to adjust the rear derailleur as the shifting was dead on. The sound coming from the new cassette as the shifting takes place was loud and crisp. The sound level is still crisp but less noticeable as the teeth began to wear and sits precisely on the chain. It feels great riding with a new cassette. I may have eliminated a few grams compared to the 105 cassette. I have put in 200 miles so far and enjoying the new cassette and deep wheels.
I had to reinstall it 4 times to finally get it shifting correctly. I am not sure what was wrong on the 3 failed attempts given each of the smaller cassettes should only fit a single position, but I wish Shimano would just make it a single piece.
Having been devoted to full Dura Ace components and drive chains for over 20 years, I've migrated to full Ultegra without any loss of quality or performance. Even with marginal weight gains, the significant cost savings of Ultegra makes it a no-brainer. If I were a paid pro I'd surely go full Dura Ace, but as an avid high mileage endurance road rider footing my own expenses Ultegra has never disappointed.
Having an 11 28t cassette on my trek street bike U found it cumbersome going up steep hills. The 11 30t cassette eased my efforts. I called with questions and was completely satisfied with the expertise i was given. Very happy with my experience.
With most cycling parts, it's about will it make me faster?
I purchased this cassette for a second wheelset. The cassette did not make me faster, but it did let me use my new wheels. Perviously my groupset was shimano 105, and I did not notice any significant differences upgrading to Ultegra.
Would I buy this again? Yes, but only because Dura Ace is such a dramatic jump up in price
Nothing overly special. It's a cassette that works well. Shifting is smooth and cassette is quiet in operation. I am using a KMC X11SL chain with no problems. I've had Dura-Ace cassettes and from a functionality standpoint there is no difference with the Ultegra cassettes.