Petethepupwrote a review of Shimano Ultegra CS-R8000 Cassette on August 26, 2019
Familiarity: I've used it several times
The basics: the cassette shifts nicely, like I expect from Shimano. The obvious trade-off from a 27 or 28 is the spread between various gears. The huge upside for my old arse is the lower end, climbing a 10% or whatever grade. Going from a 28 will likely only require adjusting the derailleur stop screw.