The Ultegra cassette has always been the best balance of price and performance. With the release of the 8000 series comes the new 11-30 cassette, which I really loved for cyclocross. Having the 30t was nice to have on steep courses over the 28 but only a little bit heavier.
Kudos to Shimano for creating a very affordable high performing cassette. Shits up and down super smooth. No need for dura ace if you have this (unless youre a weight weenie).