I've driven 2 used Focus' and a Fiesta, and in all of them the powershift was shuddering and slipping already, all with less than 40k on them. I don't trust Ford's ability to make a DCT yet... Stick with the manual.
Also, too bad the fiesta is not offered 3-door. For anyone close to 6', the door pillar is beside your face and the door armrest is way ahead of you.