I've got about 600 miles on a new Dura Ace 7900 compact crank with a DA 11-28 cassette. It works well for me. I previously used a SRAM 11-28, and the cogs are slightly different. On the DA cassette the 2nd and 3rd to the largest rings are one cog smaller than the SRAM. This puts the spacing a little bit closer for all but the largest cog. I like this arrangement. I get a better choice of spacing for up to about 7% grades, and then the 28 cog ring is a nice true "bailout" for anything steeper than that.

SRAM: 11,12,13,14,15,17,19,22,25,28
DA: 11,12,13,14,15,17,19,21,24,28