Definitely have the tranny fluid level checked.
I had mine fluid changed and it gave my tranny new life. It seems to shift quicker and smoother. Some folks change their fluid every 30K as preventive maint.
If the DSC kicked in a light would come on temporarily indicating you lost traction and the DSC took over.
Some service locations can perform a "synthetic flush" where they hook up a pump to the transmission cooler lines and circulate the old fluid out and new fluid in.
If it were mine, I'd start with a simple fluid/ filter change and see if that helps. If not,then go to a dealer and see if you had the software updated, that's the only way to tell. If that doesn't correct the problem then have the output speed sensor changed. Next would be the undesirable.