I have rented a prius for the weekend to see if it fits the way I drive, comfort and road noise. So far what I was most worried about was road noise and that seems to be fine...after all of 50 miles. The car is not smooth, seems to jerk a little on the interstate in town. It doesn't seem to be smooth if I put any pressure on the throttle. It is a new car, I am too stupid to figure out how many miles on it, can't find where to look. Could it not be set up right or will this get better or worse as some miles are put on the car?
It's sensitive to crosswinds and pavement grooves. I got used to it in a few weeks and no longer notice.
Boy, and I thought talking on a cell phone while driving was bad! Seriously, though, our Prius is very smooth on the highway. All of the controls are very tight, so it's not uncommon for a new Prius driver to induce oscillations or jerking by over-controlling. I suspect that is at the root of your problem. Tom