I recently got a brand new Focus with a DCT (with all the latest updates), and when I first got it, and when only I drove it, it shifted smoothly and perfectly. Then, my dad, a rather light-footed driver, drove it for a while (while the transmission seemed to be still in learning mode). When I drove the car after my dad used it for a bit, the shifting was terrible: it would upshift to 5th gear when rolling along at just 30 or 40 km/h, and refuse to downshift for acceleration till I stomp on the accelerator, and then after hesitation, it suddenly revved to 4000 RPM and took off with a great jerk. The car would also lurch at low speeds, switching gears erratically and unnecessarily, e.g. jumping from 4 to 5 to 3 then back to 4 within one second. Then, after about half an hour of me driving on open roads with a somewhat heavier foot on the accelerator, the car seemed to relearn how to shift properly at the right times. Now the shifts are again smooth, timely, and the car doesn't get stuck hesitating in high gears while lugging the engine trying to accelerate.
Based on my experience, my suggestion is not to baby the car when the transmission is learning. Accelerate in a timely manner, hold a decent speed, and let the engine rev to 3500+ RPM when accelerating. Doing so seems to teach the transmission that it's supposed to downshift when accelerating when the car is already in motion. Otherwise, the transmission starts thinking that it should quickly upshift through the acceleration and then remain stubbornly planted in 5th or 6th once at a semi-steady speed (even if very slow). I didn't have too much trouble with accelerating from a stop, but the car for a while didn't want to downshift to accelerate from an already moving state, and the somewhat more aggressive throttle usage fixed that shifting issue.
The DCT can be very nice when it's been properly trained: it gives good acceleration, crisp shifts, the firm feeling of direct drive, and very handy engine braking. I'll give an example of where the engine braking was very effective and handy today: I was coming downhill from an 80 km/h zone into a 50 km/h town, and all I had to do was tap the Set- button on the cruise control to slow me down adequately and hold a legal speed down the steep long hill. Didn't have to touch the brakes on such a drop. With our other car with a conventional auto, I need to apply brakes repeatedly to a significant extent to achieve the same.