The problem with the Lab conversion to CMYK is that when you get a darker colour it will not use Key until it hits over 50% of Cyan. So the end result for the poor printers is 4 colours flooding onto a sheet that could theoretically be on Cyan and Key. Take PMS 431 on the CMYK conversion in the old Indesign it was 11C, 1M, 64K. In the CC version, it's 63.28C, 47.01M, 40.04Y, 27.69K. The second breakdown in values will lead to paper stretch on the press if you have an overall background. The other thing is that it don't actually specify what profile setting is being converted through. Is it on perceptual or absolute?
Not good really.
