Just catching up on forums (haven't been online much over the past few months, and am just reading up on Nick's passing ... Two weeks ago my PowerShift wouldn't go into "Sport" mode - as if something was physically preventing it from going from "D" to "S". Took it into the dealer. Turns out a clip holding the shifter cable somehow got loose. Dealer had to open the console and get things secured, as well as did a relearn of the transmission. It was also covered under powertrain warranty.
So far, everything seems to be normal after 60,000 km. I still get the odd shudder or quirky moment, but it seems like they come after I've driven in heavy city, stop and go traffic and get back to suburbia with less aggressive stopping and going.