Perhaps I'm not as experienced with auto gearboxes, only having driven one more (Renault), but I found the Powershift more than adequate during my 2 test drives.
Yes, the change from first to second could be smoother and having a heavy foot doesn't help, but from then on it's cruising very nicely -no noise or noticeable lag. My second drive was intentionally during rush hour with bad traffic and I didn't have any problem at all -minus the start/stop which confused me at times, but that's irrelevant.
Overall pretty good for my standards and nothing I wouldn't be able to get used to easily, slightly adjusting some of my driving habits. Manual on the other hand, I found it a bit jerky.
Of course, distance makes the heart grow fonder and since my car is still miles away, I may be sugar coating everything about it!
Will see what happens when it finally gets here.