I have been having this problem for a long time, i tried changing oil and filter but it made no difference. The hard shifts sometimes occur between some gears and other times between other gears depending on the rpm of the engine. Switching to Steptronic and taking foot off gas pedal before shifting results in smooth shifts. I am not sure if it is a sensor, software, or hardware issue.
So many things can do that, Start by having a pro like me hook up his dealer level scanner and go from there.