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 got a set of climbing specific wheels and wanted a cassette that would leverage that even further. The 32-11 was a good call. I really don't use the 32 that often (most climbs are fine with the 30) but when you hit a wall and need just a little more leverage and a little more confidence, the 32 is nice to have. I was worried about chain length because my other wheelset has a 30-11, but I have had no problem. If I was moving from a 28 to a 32, I'd probably need an extra link or two, but the 30-32 switch has performed fine on an Ultergra Di2 longcage derailleur.
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.
I wanted the wide gear range available in this cassette and also was glad I could get it at a decent price. I have one of these on another bike and it has lasted a very long time. This one should also last a long time. This is a very good cassette that I'll buy again if the need arises.