Fortunately, Campy beat SRAM to the 12 speed road bike system and the cassette fits on the same hub as 9/10/11 speed. For me, the only thing I'd gain over my modestly priced Chorus 11 group is an 11T cog, that I don't need. My 50/34 with a 12-32 does a great job on very steep hills and mountain roads. I expect a Chorus 12 group, next year. I could convert my 11 speed bike to Record 12 with only the shifters, derailleurs, chain and cassette for under $1000.