I don't know what the percentage of people with DCT issues is but some time ago I created a poll to ascertain the build date where the problem lies. I found that of the 100+ people that replied almost all the people that still had problem had a build date in the first 6 months of production and that very few folks with build dates after that were still experiencing problems.
This data, though the sample size was limited, suggested to me that most of the problems was either due to early parts problems and/or assembly process. I suspect assembly was a major factor as oil leaks onto the clutches seem to be a big hitter.
I also suspect that if Ford/Gertag were to do a green sheet of paper redesign of the DCT there would be some changes to the clutches, actuators and perhaps the housing (seals). Since we current owners are unlikely to ever get any such new DCT we're probably looking at new seals and clutch replacements if we have problems. That is, when they admit there's a problem...
2012 FF Ti HB Sonic Blue, Built 5/7/12, 401A + Parking Technology Package and MFT w/NAV 3.0.2 -> 3.2.2 -> 3.5.1 -> 3.6.2