Hard to describe with words (rough, stutter, jerky, or "whatever").
Yes, I do notice something (rough, stutter, jerky, or "whatever") at times. I am guessing it is in the transmission (normal or abnormal shifting or engine misfire).
BTW, As you may have read, one poster here had serious problem "whatever" and was finally diagnosed as a mis-fire and looks like he will get a new car as they could not resolve his problem - serious "whatever" he described as stutter I think).
Anyway, as it stands now -- I am ignoring the slight 'whatever" (I call it slight) and like the car and Mile Per Gallon (around 51MPG on reported 8 fill ups - reported here and on Fuelly Web Site).
We shall see as time and miles go on. ??? In the meantime, hope their warranty works if needed.